HELP

Hey, so my father based in UAE is sending back home some of his life savings he’s made over the years, He’s recently had some Visa issues due to which his bank accounts were freezed, so he sends monthly remittance through hundi wala.My concern is this is the first time he’ll be sending a relatively big amount. I wanted to ask whether there will be any such issue sending through an account thats not declared as a source of income in my mums account. Whats the max amount he can send without being flagged suspicious by FBR. Any help/guidance would be greatly appreciated, Thanks