It seems in your company STT charge is too high then other Stockbrocker.
1.1. Trade Smart Online|| Link|January 15, 2015 10:44:43 AM
Hello Prakash Mehta,
STT is charged by Central Government and it is same percentage for all the broker in India. For your reference please go through the link for STT charges. http://www.sbismart.com/sites/default/files/Securities%20Transaction%20Tax.pdf