India

1. Go draw something. Repeat.
Practice leads to improvement. You won't get any better unless you engage in the attempt. The more you draw the more confident you'll become.
2. Look at drawings.
Whether simple line drawings or meticulously detailed renderings, you can learn a lot from looking at the work of others. How did they use line and shape? How did they shade?
3. Draw from drawings.
This may sound peculiar, but what can you learn by copying a Da Vinci or Michaelangelo sketch? Tons. Learn from the Masters by copying them. Really. They won't mind.
4. Draw from photographs.
For most people, it's easier to reproduce an image that's already two-dimensional than reproduce an actual object, person or environment. When you're working from photos, look at edges, shapes and angles. Don't trace. Draw.
5. Draw from life.
If you're just starting out, pick simple objects and work your way up to complex ones. Go ahead and try your hand at drawing people and your pets. Draw your furniture and your living spaces. Do you enjoy coffee? Draw your coffee cup. Here's a challenge: draw your hand. Hands and feet are the most complex parts of your anatomy and are readily available subject matter. If you can master these, you'll pretty much be able to draw anything.
6. Take a class.
A class will keep you accountable. A teacher will correct your weaknesses. Watching others draw is immensely beneficial for building your own observational skills. Where do you find a class? Check your local university extension, community adult school, YMCA or community college. Another source is your local art supply store, where artists post notices of drawing meet-ups, uninstructed sessions with models, or private instruction.
7. Keep a sketchbook. Meaning, keep it with you, open it up and work at filling it. It will serve as a reminder to grab your pencil or pen and do some drawing. Join the ranks of Moleskine or Field Notes aficionados, or simply pick up a sketchbook at your office or art supply store.
8. Be intentional. This is the hardest thing, because if you want to improve at anything, you must decide to do it. You need to make a commitment and even schedule regular time in your week or your day to pursue drawing. In order to become better at it you need to make a habit of it.
I think it's also important to understand why you desire or need to draw. For me, it supports my work, but it's also something that provides a lot of pleasure. I simply enjoy drawing.

Nazeer, please check the link below to know the tentative colleges that you can get with these marks
https://www.shiksha.com/jee-mains-college-predictor
Other than this you can try for admission in private universities. These days we have so many good private universities that are imparting quality education to the students around the world. They offer you admission on JEE scores/ tests conducted by them/ your marks in 12th. Some of these also offer good scholarships based on any one of the above mentioned admission criteria. Check the websites of some good universities or call on their toll free contact numbers for more details.
Good luck.