Well sir I'm traveling on this route for six years now. I can count a few for you:
APSRTC-2
HKB-3
KESINENI-2
KALESWARI-2
VIJAYANANDA-1...
more...
JABBAR-2
SAHARA-1
OMER-4
NEETA-2
DHUNUNJAYA-1
AP TOURISM-2
NAKODA-1
SVR-3
SANGITA-1
A P TOURS & TRAVELS-2
GEE PEE -1
There may be more as well. Again I am only counting the Volvo/Mercedes Benz service. There is also non-AC service by many providers