I am a student of F.Sc in Pakistan.I want to get top position in the whole Pakistan in F.Sc.I am a patient of depression.I am getting okay day by day.I want to know about best study method of study at college level.I want to go Europe for higher studies on scholarship after F.Sc.

Getting the highest grades doesn't get you through life and a good career. Some people do nothing but study and then fail socially, which is part of most jobs unless you truly work alone.
Employers look for enthusiasm and eagerness as much as where you stood in your class.
I realize that you want to go to grad school and to get a scholarship, but even those depend partly on how you present yourself, and extra-curricular work, play, volunteering, and interests.
I would suggest that you take a deep breath and work on why you are depressed. I hope you aren't just taking anti-depressants, but also having some talk therapy or being in a peer group. Many times it's more situational than chemical, pressures from family being a big one. Often the pressures become internalized and you become your own worst enemy, fighting with yourself.
One way to do well is to try to let each failure go, and move on as though it never happened. This is very difficult, and when depressed, we tend to have an 'all or nothing' attitude - I botched that paper or test or relationship, so I'm never going to succeed. Think of the athlete who just lost the game for his team, and he's miserable, and feels he's on a losing streak. The only way out is to think positively and to say that the past doesn't control the future.