Using the right question tags

We are having the party tomorrow, is it?
He hasn’t come to the office, is it?

Can someone please tell me if the above sentences are natural? Can we use is it in such situations? It’s very common here in India. Can it be considered an Indianism?

Good morning Daemon.

We are having the party tomorrow, aren’t we?

He hasn’t come to the office, has he?

Can it be considered an Indianism?

Don’t know the answer to that one mate, but it sounds as it may be so if in common usage.

Bill.

Thanks a lot, Bill!

Let’s see what the other native speakers have to say about this?

Hi Daemon,

From an AmE perspective, both of those tags sound very unnatural to my ears.

Not sure about the Indian English aspect.

Thanks a lot, Skrej!

What if I replaced is it with is it so in those sentences? Would it be OK then?

the first answer is : aren’t we?

the second is : has he?