I want to purchase 2 Bhk flat in surat Dindoli area which is constructed before gst rules are applied. So I want to know that I will have to pay "GST" for registration of I will purchase the flat??

I jointly own a row house in surat with my brother.My brother wishes to gift his part to me through a gift deed.What are the formalities,and should i have to pay stamp duty and registration fees for it,what is the rate for such deed,i heard about article 25 of conveyance.Please explain in detail.