Hello Sir,
1. The First transaction here, is a Sale of Property/ Flat. Such a Sale of Flat will attract Capital Gain, on which Tax has to be paid by your brother.
2. After paying Taxes, he may transfer the funds to his wife's name in order to make an FD, but doing so the Income on such FD will still be taxable in his own name because of the Clubbing Provisions. So if he wants to make an FD in his wife's name and avoid it getting clubbed in his own name, then it has to be pre-planned and routed well within the ambit of the act with the help of a professional. So that even your job is done and no future consequences arise.
Hope this clarifies your Query.
Feel Free to get back for any further clarifications.
Thanking You.
Regards,
CA Rohit R Sharma.