Do or make Om by saying Onkar

Yes — there is a real historical and linguistic connection between Oṃ/Aum, Oṃkāra/Oṅkāra, and the Sikh Oṅkār, although the later religious meanings are not identical. And your question about -kār is particularly interesting.

1. Start with Oṃ / Aum

The Sanskrit sacred syllable is ॐ, conventionally transliterated oṃ, and often written AUM in English.

There are actually two levels here:

• oṃ is the ancient sacred syllable itself.

• A-U-M is the traditional phonetic/interpretive analysis of that syllable.

The Māṇḍūkya Upaniṣad famously analyzes Oṃ through A, U, M, followed by the silence beyond the sound. This becomes a tremendously important philosophical interpretation: the sound encompasses waking, dreaming, deep sleep, and the transcendent fourth state.

Historically, Oṃ belongs to the Vedic/Upaniṣadic world; it isn’t simply a modern invention or a later Hindu mantra. It becomes an especially important object of meditation in the Upaniṣads.

2. Then what is Oṃkāra?

This is where your “kar” question gets interesting.

Sanskrit:

Oṃ + kāra → Oṃkāra

The suffix -kāra is related to the Sanskrit root kṛ, “to do/make,” and occurs in compounds referring to the production, making, or expression of something. Thus Oṃkāra can be understood roughly as:

“the making/uttering/expressing of Oṃ”

And historically, this is indeed how the term came to function: Oṃkāra is a name for Oṃ itself, or for the utterance/expression of Oṃ. The Sikh Encyclopedia explicitly traces Oṅkār back to the Upaniṣadic Oṃkāra (om + kāra) and describes its original sense as pronouncing or rendering Oṃ.

So kār does not mean “place.”

That’s an important distinction.

There are other Indian words containing kar/kār that can have meanings associated with a place or region, but that isn’t what -kāra is doing in Oṃkāra.

3. How does Oṅkār / Onkar arise?

Here we get a very interesting phonological development.

Sanskrit:

Oṃkāra

Punjabi/Gurmukhi:

ਓਅੰਕਾਰ / Oaṅkār, commonly rendered Oṅkār / Onkār

The relationship isn’t merely coincidence. The Sikh Encyclopedia explicitly calls Oṅkār a descendant of the Upaniṣadic Oṃkāra and says it is synonymous with Oṃ in its older usage.

So you can put them historically like this:

Oṃ → Oṃkāra → Oṅkār / Onkār

That’s a much more defensible linguistic chain than saying they are completely unrelated words.

4. But then comes the enormous theological difference

Sikhism takes this inherited vocabulary and gives it a distinctive theological emphasis.

Ik Oṅkār

is:

ik = one

oṅkār = Oṅkār

So the phrase is traditionally understood as something like:

“One Oṅkār” / “One Supreme Reality” / “There is One.”

The important thing is that Ik Oṅkār is not simply the Hindu mantra Oṃ with “one” put in front of it.

The Sikh interpretation centers on the oneness of the Divine, and Oṅkār becomes intimately associated with the One Reality and the creative/manifesting principle. Sikh scholarship explicitly notes that although Oṅkār is historically cognate with Oṃ, its meaning in Sikh theology develops in distinctive ways.

5. There is an especially beautiful linguistic connection here

Notice what happens:

Oṃ

is essentially a sound.

Then:

Oṃ-kāra

can be understood as the expression/utterance/form of that sound.

And then:

Ik-Oṅkār

places One before that cosmic sound/principle.

So there is a fascinating conceptual progression:

sound → expression of the sound → the One expressed through/identified with that sound

This is one reason the Sikh concept can sound remarkably familiar to someone coming from the Upaniṣadic/Oṃ tradition while nevertheless having its own theology.

And “Oṅ” rather than “Om”?

The ṃ in Sanskrit oṃ is a nasalization. In different Indian linguistic environments, the representation and pronunciation can shift toward something like oṅ / ong. Sikh pronunciation and Gurmukhi orthography preserve a form conventionally transliterated Oaṅkār/Oṅkār, hence the familiar English Onkar/Ongkar.

So “Ong” isn’t necessarily evidence of a completely different original word. It can be understood within the historical phonological development of the term.

6. One caution about the “A-U-M” analysis

There’s a subtle distinction worth making.

It is common today to say:

A + U + M = OM

and then give each sound a cosmic meaning.

But linguistically, that doesn’t mean the historical Sanskrit word oṃ was literally constructed by somebody taking three independent words/sounds A + U + M and combining them.

Rather, A-U-M becomes a traditional phonetic and metaphysical analysis of the already sacred syllable Oṃ.

That distinction becomes important when you’re trying to reconstruct the actual linguistic history rather than the later spiritual symbolism.

The short answer to your question

Yes, Oṃ, Oṃkāra, and Oṅkār are historically related.

Form

Basic sense

Oṃ / Aum

sacred syllable

Oṃkāra

Oṃ + kāra; expression/utterance/form of Oṃ; also a name for Oṃ

Oṅkār / Onkar

later Indo-Aryan/Sikh form related to Oṃkāra

Ik Oṅkār

“One Oṅkār,” the Sikh expression of the One Supreme Reality

And kār does not mean “place” here. It comes through kāra, connected with kṛ, “to do/make,” and in Oṃkāra functions in the sense of the making/uttering/expressing of Oṃ.

There’s actually a very interesting next step to this question: we can trace Oṃ → Oṃkāra → Oṅkār → Ik Oṅkār through Sanskrit → Prakrit/Apabhraṃśa → Punjabi, including the actual phonetic changes (especially ṃ → ṅ, loss/change of vowels, and the shortening of kāra → kār). That would get much closer to a genuine historical-linguistic reconstruction rather than just comparing dictionary meanings.