It doesn't matter which laptop you are having. Just go with any laptop under 40000 range. You can go with any brand from HP, Dell, Lenovo,

i3 is sufficient but if you want the processor more efficient then you can choose i5. i5 is more than sufficient. Do not go for i7 as it is just a waste of money.

If you do not have any budget problem then you can go with Mac book Air. It is one of the best laptop when it comes to the battery durability.