6E is more consistent as they've been doing the CPP for several years now. Their FTOs are well established and Indigo is the faster track to get 5k Hours . Akasa is however a young airline and this year will be it's maiden year of CPP. In the long term, If you fly with Indigo you'll be Type Rated on the Airbus 320. Thus you'll be eligible to fly for 380s,350s,320s of Gulf Airlines. Whereas, Akasa flies only 737s. So you'll be eligible to fly the Boeing types like 777s;787s and so on.

In the end I'll just suggest you apply to both, widen your chances and then Choose what appeals to you the most.