#2 Federation Cup, Reserve league and Durand cup
The AIFF should have a knockout tournament, running alongside the league calendar, with adequate breaks in between the 22-game league. Teams from the top two divisions should be allowed to compete in it for starters, and it could slowly expand to include regional teams as well (as and when the league expands).
The Cup should be played in a knockout format, with the bottom teams facing each other first, and the top teams joining in later (much like England's FA Cup). This tournament could be called the Federation Cup, and have the same format as it was played in 2016, with two-legged ties, and a glamorous final match. The winner of the Federation Cup must get the AFC Cup spot, thus giving clubs a huge incentive of playing this competition.
Apart from the top two divisions, the clubs which have reserve squads should be playing an AIFF, or a reliance organised reserve league. This could be played as an age-category league (say U-21 or U-22), or could be played as an open category league, with no foreigners.
This league does not have to be marketed at all and could be played at smaller, practice pitches even, with the main aim of giving younger players more playing time. This league would help club scouts identify talented youngsters, and would create a wider pool of younger talent, raring to go in the top leagues sooner or later.
The Indian Arrows, being a non-commercial project, could play their games here. In this way, the arrows project, along with its benefits is still maintained. The Arrows boys would get great exposure by playing reserve teams of big clubs.
The reserve teams could also be allowed to participate in regional knockout cups (and not leagues), and this league could be adequately spaced to accommodate all of this. Since this league would need minimum marketing, prize money could also be kept lower, with the main aim being to find players worthy for the first team, and in turn the national side in the future.
The Durand Cup, Asia's oldest cup competition, should be remodelled alongside other pre-season cups like the International Champions Cup and should be given the status of India's main pre-season cup for all the top clubs.
Good foreign teams could also be invited, so as to generate public interest and revenue, as well as better match practice for the Indian teams. These foreign teams could be extended invitations to conduct their pre-season camps here in India and could, in turn, invest in Indian football, hence benefiting the clubs, as well as AIFF.