What happen if sold my all holding today and bought at same price at lower price same day to hold again

i have sail shares with avg of 128.05 245 qty today i sold those shares and again placed order for same amount of qty of 245 with price of 121 so i can get avg of this??

Selling shares from holdings and buying back the same day will be considered as intraday trade. This doesn’t have any effect on buy average.

The difference between the price you sell and buy back at will be your realised P&L. You can check out more on this here: