They will have to apply for a PRTD from the consulate or try entering from the US border. Needless to say that if they have been in Dubai for 10 years now, the chances of them having a PRTD approved is zero and they will start the process of revoking his PR status for non compliance of RO. He would also likely be reported if he crosses the US border for RO as well. Realistically he needs to understand he failed to meet RO, and while he may have been able to claim H&C for family reasons in India, he should have returned 10years ago to be successful with that. His 10years in Dubai will work against him and he will quite likely loose his PR status.