One Strategy is
Get IDFC Vistara, SBI Vistara(Basic) and Axis Vistara(Basic).
IDFC Vistara: Make all you spends on this - ~4.5L = Get 4 Premium Economy ticket - 30k Total Value(7.5k each)
SBI Vistara: Spend no money here if your spends are 4.5L, if it is higher than that, then spend here, get 1 ticket atleast worth 6k
Axis Vistara: Same strategy as SBI Vistara, 1 ticket
Fees paid total: ~10k
Benefits: 42k(From IDFC, 6k from SBI, 6k from Axis) + 13500 CV points for spends on IDFC(worth 13500)
Total - 55k on spends of 4.5L ~12.2% reward rate.
Plus points through paying rent is able to negate the fees for paying rent through a CC, hence pay rent through these(which would have been paid otherwise through cash or debit card and get economy tickets for free on top of this.
IDFC Card will give you the silver tier membership and the insurance which surely will cover all the use cases and no point in taking prime versions of axis and sbi vistara card
P.S. - This would suit only for moderate spenders of ~4.5-5 lakhs