BTST : Can I sell on T+2 without worry of short delivery

For example, I bought share on Monday, as per schedule (T+2 ) I should have it in my account by wednesday evening. But the seller has didn’t deliver, so I am getting the share on T+3 that is on thursday. So my question is if I sell the share on Wednesday mornring(as I will be having the share on thursday), so is there a chance I am also not able to deliver the share ?

Your logic is correct, even if the seller defaults, you will have the shares on T+3 from auction to deliver for the shares that you are selling on T+2. 

But there is still a very very small risk that always exists. What if on T+3 day, exchange is not able to get the shares and decides to settle in cash? See the last point on this post