Gift deed

I had received a cash gift of Rs.40000 in 2014 and Rs.200000 in 2015 from my grandmother, till date i had not prepare any gift deed.Can you please advise whether i can prepare it now with current month date or not whether this need to be on a stamp paper and notarised or the details can be written on plain paper and sign by the donar and donee.Is there a fixed format to write the deed or it can be drafted in own words with all the details and whether also is it necessary to provide the reason why the gift was given