In expiry week can we carry forward out of money stock options overnight or is there a restriction and it is blocked?
There is no restriction as such, you can carry forward your position, you just need to have sufficient funds as margin requirements increase for Short positions during last two days of expiry week.
Is this even true for Nifty and Banknifty or only for stock options ?
This is true only for Stock Options as these are physically settled, that is why additional margins are required during expiry week. Nifty and Bank Nifty Options are cash settled, no need of additional margins.
Can one buy fresh long postions in otm calls/put from Wednesday afternoon and cut the position on Thursday before close. As i got an email from support saying fresh long postions cannot be opened on Wednesday…
“Thank you for writing to Zerodha.
Fresh long option positions will not be allowed on Wednesday and Thursday of the expiry week”
Is this true?
You cannot do this.
Yes, this is true. Fresh long positions aren’t allowed in Stock Options on last two days of expiry week.
But sir… Options need to be settled before or at the expiry date… Then how can any one carry forward the options contact???
Need a clarification sir…
Your little help can make wonders 
Why sir… If one wants to intraday… Then…?
You cannot carry forward your position beyond expiry but say if you take position on Tuesday, then you can carry it forward to the next day.
Intraday too isn’t allowed. You can read this to know more.
If I am holding long naked futures position will there be extra margins in expiry week?
Yes, for Stock Futures margin requirement will be twice of the SPAN + Exposure margin on last two days of expiry.
By last two days does that mean from tuesday evening?
Wednesday Begining of the Day.
Has this also changed because of the new rules from Dec 1?Was it not Wednesday EOD where i would need the extra margins and not BOD?
if i am long from tuesday evening (no extra margins) Will my position then be squared off on Wed Morning if there is lack of margin?
So for short put position in expiry week …we have to make sure that we maintain double the margin before beginning of Wednesday 9.15 am - market opening correct?
Also, I think I understand about double (span+exposure margin) but when will you require full contract value ? will it be on next day after expiry Thursday or before 2 pm on Thursday or before 3.30 pm on Thursday?
I guess you will require full contract value only on Friday because until than no body will know if it will be assigned (ie. if you have to take delivery or not) correct?