Cost of surgery varies between hospitals and definitely between cities. There is no"average" cost.

Conventional Dissection Tonsillectomy is gradually being abandoned by most ENT Surgeons for either LASER or COBLATION surgeries as these procedures are safer, relatively painless and offer faster recovery and can be done as daycare procedures. Costs patients about ₹60,000 to ₹80,000 here in Bangalore depending upon the hospital. I suppose it could cost another 20% more in your city.