Under 5 laks you have options like alto, wagon r, spark, eon, i10 , Chevy beat , figo and Nissan micRa . You can go have test drives of this cars and decide which you want all are good capable cars .
Other then fuel efficient is there anything you are looking in the car ?
If you stay in Mumbai or Delhi wagon r cng option will be give you very very good mileage .
So these are the requirements-
under 5 l, there are hardly any family sedans in the market, so you better keep with hatchbacks.
If fuel efficiency is the only criteria, then according to me, you should consider these cars priority wise-
1.Alto k10 vxi
5.chevy beat ls/lt
Other cars available are-
santro, ritz, figo, alto, astar, vista, etc.
also look at toughguy's list.