Nps to gpf

You may not be allowed to do so now.

There are dedicated blogs/persons for such queries.

You may try and ask them e.g;

https://90paisa.blogspot.in/2009/08/new-pension-scheme-key-points.html

However if it is erroneous contribution then you may try in line with :

PENSION FUND REGULATORY AND DEVELOPMENT AUTHORITY

Cir no: PFRDA/ 2013/2/ PDEX / 2 
SL-1

Subject: Withdrawal of erroneous contribution received into NPS instead of GPF

You may approach through your PAO/DTO/DDO to  NPS claims cell at CRA of PFRDA

https://www.gconnect.in/nps-2/nps-contribution-received-into-nps-instead-of-gpf.html