violet7 and footyfan: thanks for your reply.

Does transferring the case to another centre have any impact on this 150 days thing? NY office said they will transfer his case to CHicago but he has no idea how long will it take to trasnfer the case.  Can he apply for EAD no matter how long it takes to transfer the case? Is his clock (of 150 days) stopped when trasnferring the case or he should be fine applying for EAD after 150 days?

It would be a great help if anyone can provide some information regarding these too.