Buying a smartphone below Rs 7,000 requires more care than buying a smartphone that costs Rs 20,000 or above. In the upper range even the bad ones will not be as bad, but in the entry level category you can get stuck with phones that won't work for you because they have too little in terms of hardware to be able to work smoothly, or they simply have very poor implementation.
So the first thing that you need to do is not to buy an Android smartphone with less than 512 MB of RAM. Don't buy a phone with a very small battery (we will soon give a matrix to decide on the size). However, generally speaking 1450 mAh is what you need if you are considering a 4-inch device; 1250 in case of any Android phone.
We have made some selections for you, which we think are the best phones south of the Rs 7,000 price point. We have not taken really entry level price points in consideration and will address those separately later.