Hi laskhya ,

Yes buddy , you can study 16 hours a day. But here what matters is not the number of hours you study but ' how effectively you study in even minimum number of hours'.

But if you do want to give it a go and then want to study for 16 hours then try to follow these;

1). Be determined enough to sit on chair and table rather than on a couchy comfy bed

2). Take short gaps in between. Atleast 15 to 30 mins.

3). Keep a water bottle near you and try to drink it as much as possible. This will keep you hydrated as well as you won't jump for naps. Don't rely on tea or coffee for this.  Drinking Water is the best  solution.

4) Rest study with full concentration.

I hope it might have helped you.