Since, it seems for the most part like you’ll be riding in what appears to be a flat city that has many un-improved roads I’d suggest the Fusion from Firefox bikes:http://www.firefoxbikes.com/fusion.htm
* 18" Enduro steel frame.
* Front suspension fork.
* Alloy rims
* Shimano 6 speed gears systems with V-brakes.
* Color: Blue / Black
Red / Black
MRP: INR 7,495
The steel frame and front shock should soak up much of the jarring from the ride while also being much lighter than a full suspension bike. The steel frame should also have a longer service life than aluminum.
In a flat city like yours I can’t see that much of a need for the added weight, cost and complexity of anything much more than the 6 speed gears.
If I were in your shoes this is the bike I would buy for the purpose you asked about.