Off-market transfers of unlisted shares with consideration will attract a 0.015% stamp duty.
Say if you are transferring securities worth 100,000 INR, stamp duty @ 0.015% will be 15Rs.
Method of paying stamp duty varies as per the depository you are having an account with CDSL or NSDL. Links to payment for stamp duty
NSDL- To calculate and pay stamp duty in NSDL (Click Here)
CDSL- To calculate stamp duty in CDSL (Click Here) . Make payment for advance stamp duty through NEFT/RTGS/IMPS only from any bank through the online portal of respective banks or by submitting the physical forms to the respective banks.