I have also been looking for high intraday margins for futures with minimal brokerage, & I have come across wisdomcapital, aliceblue & asthatrade as the contenders so far. Astha seems ok, wisdom has mixed reviews & there aren't a lot of reviews about aliceblue on Traderji.
If trading only one lot or two lots then wisdom or astha might be ok whereas for more lots, aliceblue might be better since I THINK they charge Rs.20 max but I'm not sure about this yet since I can't find it on their website (which in itself seems a bit shady).