Property purchased through POA

A plot was purchased in 2003-04 through POA. But it's registry was done in 2015-16. Everything done through cheque, no cash.

Query:
1) Which year will be taken for cost of acquisition ? 2003-04 or 2015-16 ?
2) In case if, 2003-04 would be taken as cost of acquisition, than how indexation of registry charges will be done ? From 2003-04 or 2015-16 ?

Thanks & Regards