Btwin Riverside 3 Trekking bike is the best bike at that price in India. I have been riding one since the last 11 months and should say that it's genuine value for money.
Looking at your height, you should go for "L" size.
There are a host of other options in the market and each is more confusing than the next.....the buyer ends up either buying the wrong bike or doesn't buy at all.
For me it was the looks, the geometry, the build quality, the lifetime warranty and the easy availability of parts that sold me on this.
Good luck !!
Wowww. Good luck and post pics to add you to the Riverside family.