Wanted to understand, is it good to sell ITM Calls or Put of NIFTY?
E.g - Jun 11000 PE was trading at 1600 on the 1st day of expiry and last day close was 710.
Here do we lose entire money as Nifty has not crossed 11k or will get (1600-710)?
Also what will be the STT charges?
Already answered first two parts of your question here.
You should chose which Option to trade based on your analysis and strategy.
If you had Shorted that Option you would’ve gained 1600 - 710 = 890 * 75, if you would have Bought you would’ve lost 890 * 75.
Now coming to STT:
STT is charged only on Sell side at 0.05%. When you Short an Option STT charge is already accounted for, so irrespective of where the Option expires ITM or OTM there won’t be extra STT levied.
For Long Option positions left to expire, there is no STT if Option expires OTM as it expires worthless. For ITM Options, STT is charged at 0.125% of their Intrinsic Value.
So will it not be beneficial to create/write (credit) spreads on both the sides in ITM strikes?
You can do whatever you want, just keep in mind writing Option carries unlimited risk.
If you are new to Options, read this
Options module on Varsity to understand more about Options.