Hello satyajeet sahani. Answering your question- Yes you are eligible to appear in jee main examination as you have studied the basic subjects which are needed and hence you are eligible for the exam.The question paper of jee exam consist of 3 sections which are physics, chemistry and maths.Each section are of equal weightage and the question paper is of 360 marks and the time  allotted for exam is 3 hours.You should score the minimum marks to qualify the exam .Hope this answers your question.