You will have to pay stamp duty and registration charges.
Stamp duty varies from state to state.
In Maharashtra, it is 10 per cent of the market value as assessed by the Stamp Office. The process is as follows. The stamp office affixes the stamp for the said value. The agreement then needs to be registered. The property agreement should be registered with the Sub-registrar of assurances under the provisions of the Indian Registration Act within four months of the date of its execution.