Hey Uzma

Preparing for JEE Mains within 3 months from scratch will require a lot of dedication and consistent in the whole process. You can look following tips for help:

• Look into your strong topics and concepts (The one which you were confident in Boards), note them down and start strengthening them
• From the strong topics, read the theory from standard books and practise the questions from NCERT and reference book you are following
• After the above process, go through JEE Mains syllabus and start finishing the easy topics according to you, follow the same method of reading theory and practising questions
• You must make a target of practising good amount of questions every day, this way you will get hold o problem solving
• For Maths, try memorising formulas and solve questions everyday
• By this about 2 months will fetch and you would be able to cover good amount of syllabus
• Start solving previous years and give mock test, from them analyse your mistakes and work on them, make sure not to repeat any mistakes in consequent paper
• Be consistent and motivated throughout the process for better outcome
• Be focussed on standard books only

You can check the crash course, available for JEE Mains: https://learn.careers360.com/knockout-jee-main-april/