Hari Om Kalpanaraja-ji,
Matapalli is in Nalgonda district in AP. Take a train from Chennai to Vijayawada. From Vijayawada take a bus to Kodada. From Kotada you can take a cab to Matapalli. Anyone will be able to guide you to Matapalli from Kodada.
Also you can take a cab from Vijayawada directly too if you wish.
Hope that helps.