There is a statement issued by BCCI regarding the new rule of IPL 2023, according to which now the captain can choose their playing 11 even after the toss. This rule requires the captains to come with different team sheets as per the toss results. They can hand over their final 11 with the appropriate impact players included.
According to the playing conditions clause 1.2.1, "Each captain shall nominate 11 players plus a maximum of 5 substitute fielders in writing to the IPL Match Referee after the toss."
Other than this, according to Clause 1.2.9, "no player, i.e., a member of the playing eleven, may be changed after the nomination and prior to the start of play without the consent of the opposing captain."
This simply means that after the toss, if the captain of the team feels that he needs to change the line-up, he can do so until the match starts.
One more change made to the playing conditions is penalizing unfair movement by the wicketkeeper in case there is a shift in position before the batter meets the ball.
In this case, either umpire shall call and signal dead ball and inform the other umpire of the reason for doing so. The umpire present on bowler end can "award the one-run penalty for Wide or No ball, if applicable or award 5 Penalty runs to the batting side.  Inform the captain of the fielding side of the reason for this action. "Inform the batters and, as soon as practicable, the captain of the batting side of what has occurred."
Another change called "Impact Substitution," in which a player can be introduced during the match from the five decided substitutions, had already been announced by the tournament committee.