No with same pnr, you can continue till Agra only.look for other alternative for Delhi
The destination can not be altered once it is booked. Although, IR has given option to change boarding point as you want but not in case of your destination.
I recommend you not to cancel the booked ticket & book another one in same train if available.otheriwse , there is bunch of train for Delhi from Agra , book it a/c to your time schedule.