One year for AoN two for RFP and two more for evaluation. By then multiple N-IMRH would be flying. Cancel wait for the full certification like spike, htt-40 etc. Official timeline is 7-8 years. IN version is separate and it would go in parallel. IAF/IA doesn't have an urgent requirement like IN so it could be a priority.The DAC approval for NMRH will come around the time the contract for 24 is signed.
HAL's IMRH is more than a decade away from a naval variant.
Any casual observerer would understand the pattern by now. Expecting IN to order all helis as import is very unrealistic.
BTW LCA mk2 can be designed and certified in next 6-7 years but a medium hell can't? You should optimize your optimistic viewpoint towards a wider area.