Member is required to inform change in professional address to the Institute's office within 30 days from the date of the said change.
a) A written request signed by him is required to be submitted.
b) In case the new professional address of the member falls in other region, the request should be submitted to the decentralised office of the previous region.
You can go to icai website , go to members sections, click on update the residential address and professional address. Enter your membership and date of birth. Update the address, take the print out of same, sign it and send it to concerned decentralised office of institute.
I hope this will suffice.