It is obvious that SEBI members is friends with big option sellers or they themselves is option sellers, what option sellers want on expiry day? close the index at strike they want to eat all the premium. Removing calendar spread is another proof, now we are forced to buy expiring hedge so those big option sellers get even more premium.
By raising lot size they can kick small option sellers out of market, what is the result of this? raise in option premium like American market, which means more premium for big option sellers.
Our market is not even volatile, its moving max .5% either side on daily basis, they made up all BS stories to change the market for their benefit, and to raise tax.