Is it possible to join with another company when H1B is in IR status?

Am currently working in a company X in India.
And got a H1b offer with company Y also they filed the H1b petition. It is in initial review status now.
In the meantime, I also got an offer with company Z in India. Is this possible to change the company from X to Z.

Will it affect my H1B status / offer anyways ?

Yes, you may change your employer in India. It will not have any effects on your petition.