place of supply of services

Sir pls. Clarify my doubt
Our regd. Office situated in hyd. We are authorized service provider for home consumption ventilators in India for company situated in USA. We will service warranty machines (which are under warranty) as a free of cost to Indian customers. The amount will reimburse by head office situated in USA. We have to bill goods, services separately to USA address. Now my doubt is these transactions comes under interstate or intrastate supplies? supply of goods & services done at Hyderabad office to individual customers situated across India.