Trending @Infosys; How much time it takes from SSE to get promoted to JL4?

For Banglore DC IJP promotions have already started . You can ask your manager to put our your name for this current promotion cycle. It will depend on just 2 things

1. Role maturity eligibility
2. Rating from previous Quater cycle.

I'm not exactly sure about this, but I heard from seniors that officially a minimum of 3 yrs are required.
Also, that too depends on your relationship with your manager.