Listed below is a short overview of the major exams conducted in India.
JEE Main: JEE Main consists of Paper 1 and Paper 2. Of which Paper 1 is for engineering aspirants, and Paper 2 is for candidates to architecture and planning courses. National Testing Agency conducts the exam. The questions for both the papers are objective types. Physics, Chemistry, and Mathematics are the 3 core subjects for paper 1. More information is available on the official website.
JEE Advanced : This the second phase of engineering exams, which is conducted by different zonal IITs on a rotational basis every year. Candidates who qualify for JEE Main are eligible for this exam. JEE Advanced is for the purpose of getting admission in the top IITs or CFITs in India. The exam is conducted only on Paper 1 and 2. Questions are based on three subjects: Physics, Chemistry, and Mathematics.
BITSAT: Birla Institute of Technology and Science Admission Test (BITSAT) is CBT [computer based Test] for seeking Admission to Integrated First Degree Programmes of BITS Pilani Campuses in Pilani, Goa, and Hyderabad. The exam consists of 4 parts and is held for 3 hours duration. It has its own marking scheme for the MCQs. The Exam is held in English only.
VITEEE: This exam is held for admission to the Vellore Institute of Technology. It consists of 5 important subjects: Physics, Chemistry, Mathematics, Biology, Aptitude, and English. The questions are objective type and are held for 2 hours and 30 minutes. The questions are set only in English. For more detail check the official website.