JEE Main

280+ in JEE Mains for general category.

50 in Advanced of JEE Mains.

Yes, what Sohan Kumar said is right. I want to add some extra information.
JEE Mains has total of 90 questions each carrying 4 marks.
Total-360 marks
And there's negative marking also 1/4 negative for 1 wrong answer.

You basic concepts related to PCM subject needs to be cleared. You can refer to RD Sharma for mathematics.

Yes, you surely can. But you should practise a lot and maintain a proper schedule all throughout the year. Get your basics clear and move ahead and also don't forget to practise previous year's questions, you will learn a lot from that.

Make sure that you are really very interested in preparing for JEE Mains. If you are then you must have a strong reason for its preparation. Whenever you get demotivated think about the reason and then you will automatically get boosted up.

Hello Amir,
Unfortunately you are not eligible for the same.

Hi,
The advantage is that you will be able to know how to manage your time in the examination and how to attempt the questions in a uniform manner because time management is very important in the JEE Mains examination and writing many part test will make you confident and you will be able to know your weak and strong areas in the subject by knowing the mistakes that were done at the time of exam, if you correct them then you may not repeat the same thing at the exam. So, try to attempt as many tests as possible.