Dear Mr. Laijesh ,
You are acting as an intermediary between main service provider and client . The amount of Service tax u have to pay depends on your status as a pure agent or not .
To qualify as a pure agent under Service tax laws certain basic conditions are to be satisfied e.g.
1. The Service Receipient should not u are acting as an agent and who is the main service provider .
2. U should not have any control on price to be charged from service receipient . i.e. Service Receipient should clearly know how much are ur service charges and how much main service provider has charged u for the particular service .
3. There should be valid agreements between u and service providers and u and service receipients which should reflect u are acting as an agent in the whole process. etc.
In case u satisfy the above conditions , u are liable to pay ST on only Service Charges as main amount charged by service provider would be reimbursable in nature . i.e.
In case u do not satisfy the above conditions , u are liable to pay ST on Rs 250. However u can take cenvat credit of ST charged by the Service Provider .