JEE Main

The National Testing Agency NTA conducts the Joint Entrance Examination JEE Main to shortlist candidates for admission into premier institutes like NITs, IIITs, and other government-funded technical institutes (GFTIs).
It also serves as the qualifying exam for the JEE Advanced for admission to the Indian Institutes of Technology (IITs).
Candidates must have passed or appeared in class 12 or its equivalent from any recognized board to be eligible in the applying year. Since NIOS is also a recognized board, candidates are eligible if they have passed the 12th at NIOS.
There is no age limit for appearing, and candidates can appear in the exam in three consecutive years from the year of passing class 12th.
You attempted JEE Main in 2022 after passing the CBSE board in 2020, and you had three consecutive chances in 2020, 2021, and 2022, according to you. In 2023, you'll have your NIOS marksheet, and, considering 2022 was your first attempt, you are eligible for JEE (Mains) under the NIOS board.
You are not eligible after three consecutive years of passing your 12th. To get more clarity, you may visit the official website of NTA.

According to CSABs notification dated March 22, For the candidates to qualify for admission in the Indian Institutes of Technology (IITs), National Institutes of Technology (NITs), Indian Institutes of Information Technology (IIITs) and such Centrally Funded Technical Institutions (CFTIs) whose admissions are based on JEE ranks, they should have secured at least 75% marks in the 12th class, or be in the top 20 percentile in the 12th Class exam conducted by the respective boards. For SC, ST students, the qualifying marks would be 65% in the 12th Class exam. So your 12th aggregate marks should not be less than 75% if belongs to general/OBC.

Mechanical engineering skill set and knowledge will be one of the biggest driving force behind product development, innovation, Intellectual property ( patents) and quality of manufacturing in India. Now a days the scope of mechanical engineering is expanding beyond its traditional boundaries and is more of inter disciplinary in nature. Mechanical engineers are focusing their attention towards new areas such as nanotechnology, development of composite materials, biomedical applications, and environmental conservation. With this shift in paradigm the new job avenues have been opened for the mechanical engineers. Big players are going to setup their manufacturing plants in India. List of some of the Top and best private colleges in India are the following
LNM Institute of Information Technology, Jaipur
Vellore Institute of Technology, Vellore
Manipal Institute of Technology
SRM Institute of Science and Technology, Chennai
Dayanand Sagar college of engineering, Bangalore
Geeta University, Panipat, RV college of engineering, Bangalore
BMS college of engineering, Bangalore