Hello,

Answers to your questions are

1)

• Create an effective, efficient, productive and well-thought Study Plan.
• Add some Break: A break will revive you and energize you to continue your studies
• Create small notes for quick revision to save time during preparation.
• So 4 to 5 hours study starting form 11th class will be helpful for JEE . As the exam date approaches, say 6 months from the JEE Mains, the study hours need to be increased to 8 hours . Give more focus on revision and solving last year's JEE Mains and Advanced question papers.
• Don't stay awake late in to the night. Be in bed by 10 or 10:30 p.m and make this a habit at least 30 days before the exam.
• Have a light dinner and breakfast
• Don't wake up too early.
• There is a best saying for your question"if I have 8 hours to cut a tree, I will sharpen my axe for 6 hours". So,Try to achieve a balanced routine rather than just sitting in study chair for longer hours. First you figure out the time when you have better concentration. If you are more comfortable to study in night then choose night, if you are more comfortable in morning then choose morning. Make sure that you are having a sound sleep of at least 6 hours per day. If possible try to catch a small cat sleep in the afternoon. This will refresh your mind and your efficiency will improve. You can mix up two activities together too. Just try to make your breaks at the time of works of your daily routine e.g. Breakfast, bath, lunch etc. In this way, your breaks between study periods will be more efficient and you will also save time. I strongly suggest you to get involved in some kind of physical work like playing some game for a period of 1 hour regularly. This will take care of problems like insomnia. When you are physical tired you get sound sleep and thus wake up more refresh. Do not waste time by playing games on computer or watching TV for longer time because they will not give your mind proper rest. A good diet comprising of fruits and milk will keep you healthy. Mind it that for a good concentration, a healthy body is very important.

2)

• Start with the NCERT.
• Have a Curious Mind.
• Solve with the Multiple Solution Technique.
• Revise Wisely.
• Manage your Time Efficiently.
• Solve Multiple Mock Tests.
• Choose the Right Reference Books.
• doing hardwork, understanding each and every concept and the technique to apply them.
• Don't let yourself get demotivated

So you can crack JEE mains without coaching by starting the preparation early, doing self study, concentrating in class, understanding your strengths and weakness,be familiar with Exam pattern and syllabus,do online study,clear you doubts, manage the time, use it effectively

For further details visit the below link:

https://engineering.careers360.com/articles/how-can-i-crack-jee-main-2020-without-coaching

Hope it helps

Best of luck!