Want to make agreement legally

A. Do you have Sale Deed copy in the name of your father's name?

B. If yes, you can apply for mutation or transfer the flat in your name or mother's name.

C. After the demised your father without a will, yourself and mother will  have equal share over the property.

D. In the absence of Sale Deed, apply EC in jurisdiction sub registrar office, then you may know the Sale Deed transaction date and property register number. Later, you can apply the same document before the sub registrar office for certified copies.