As I am slowly budding into this hobby I happen to build my first glow plane and got a futaba 7c tx + rx and was wondering what do I need to power the receiver (R617FS) and servos (S3004)...still not sure which battery pack to be used and where to buy it in India ?

Your radio may have come with a 4.8v NiCD receiver pack.  If not, that is the standard one to get.  There are alternative, and they are better for many reasons. See the thread below for a discussion on receiver batteries.  Many stores carry different varieties of suitable packs.

http://www.rcindia.org/batteries-and-chargers/you-experience-with-lipos-for-receivers-and-transmitters/ (see the poll also on top of this thread).

Most of the discussion is about TX packs, but there is useful information about RX packs too.

See this thread also :  http://www.rcindia.org/batteries-and-chargers/suggestions-for-rx-batt-pack/