To handle peer pressure, get clear on your own values and goals, learn to say no politely but firmly, and choose friends who respect your choices. Peer pressure loses its power when you are secure in what you want, because you do not have to follow the crowd to belong.
Know your own goals. When you are clear about what you want (your studies, your boundaries, your plans), it is far easier to resist pressure to do otherwise. Confusion about your own path is what makes pressure hard to resist.
It is okay to say no. You do not owe anyone an explanation for protecting your time, values or studies. A simple no thanks, not for me is enough, and real friends respect it.
Separate good pressure from bad. Some peer influence is positive (friends who study hard push you up). Bad pressure pulls you toward things you will regret. Notice which is which and lean toward the good.
Example: A Class 12 student in Pune felt pressure to skip studies and always hang out. He started being honest, I have goals, I will join sometimes but not always, and kept friends who respected that. His grades and friendships both survived.
Choose your circle. You become like the people around you, so spend more time with peers who share or respect your goals. You do not have to cut others off, just balance your time.
One practical tip: Before giving in to any pressure, ask, will I be glad I did this next week? That one pause separates harmless fun from choices you will regret, and makes saying no much easier.