Maruti Suzuki 800 [2008-2014]
₹ 2.19 Lakh Onwards
You cannot compare Nano and 800
Tata Nano is a city car which has a rear mounted(which is a new in India) engine. Maruti 800 has proven all around the highway and city and has more power and cubic capacity than a nano.
Tata Nano is 624 cc, 2 cylinder, MPFI,35BHP
Maruti 800 is 796cc,3 cylinder,MPFI with 37BHP
Now to decision making:
If you want peace of mind,reliability,resale value Go for MAruti 800. If you are ready to embrace new things you can go for Nano.
If i was in your shoes i will go for Maruti 800 and not even think of Nano.But if i am looking for a specific city drive car for two people then i will go for Nano.