You have forgot Interactivebrokers.
They have fixed and tiered commissions. commissions are paid only by opening positions when you close your positions in the same day.
I have calculated by USDINR futures by fixed and by tiered
1 contract buy USDINR futures price 60,0000 and sell price will be the same 60,0000. Traded value 120000 INR
fixed commissions is 0,01% for only 1 leg 60000 INR=6INR commissions
ExchangeTransactionCharges-0,0019% from 120000 INR=2,28INR
SEBI Turnover Charges 0.0002% from 120000INR=0,24INR
Stamp Duty (Maharashtra)0,002% from 120000INR=2,4INR
SecuritiesTransaction Tax only for sell 0,01% 60000INR=6INR
Service tax will be charged on brokerage amount and exchange transaction charges at prevailing rate (14.50% currently) 6INR+2,28INR=8,28INRx0,1450=1,20INR (service TAX)
total for round turn 6+2,28+0,24+2,4+6+1,20=18,12INR
by tiered is commissions
=< 50 crore (500,000,000) 0.012% 9 of Trade Value
50 =< 125 crore (1,250,000,000) 0.010% 9 of Trade Value
=> 125 crore (1,250,000,000) 0.008% 9 of Trade Value
by 0,012% would be
commissions 7,20+2,28+0,24+2,40+6+1,38=19,50 for round turn