The Duleep Trophy should be played as a five-team group, with the top team clinching the Trophy, to avoid drawn finals and first-innings leads deciding the winner. It should be played in the off-season, when the best players are available, no international/reserves/futures cricket on.
The Ranji Trophy needs to be shortened, and instead of this unequal hierarchical tier system, we should have three or four evenly-balanced groups and the top six make a super group stage, to keep the competition more active and reduce draw-pinching. Overseas players in off-season should be allocated to each team, which will keep the quality high when Indian players are away.
The Challenger Trophy should not be a means to select the national side. You can get nothing out of the tournament in this form. You can, instead, treat it as a workout for the current ODI team. ODI selections should be based on other tournaments.