Firstly, you will have only 80% of the released funds made available for buying on the same day. Rest will be blocked under delivery margin and available the next day. Secondly, if it is non-BE stocks buy average does not get impacted and it feels as if it is a intraday order. However, in case of BE stocks (those in T2T category), it follows FIFO. So you get the buy average of the price you bought today.
So, if you have funds, I think - Yes, it is possible to sell your holdings and buy it on the same day with caveat of avg. buy price being the price you bought the shares on today.
You can sell the shares and buy again the same day. Though, this wouldn’t be considered as an intraday trade. You can check this article to learn more.