B.Tech Scope

Yes in some institutes and No in some institutes, it's possible to study M.Sc. In Physics after B.Tech in Mechanical Engineering. But only few colleges are giving chance for B.Tech students like Delhi University. Do some research about colleges giving this chance and join accordingly.
You would only be accepted to a few institutions if you wanted to pursue an MSc in physics. Traditional universities will not even accept you for a master's degree in physics. Furthermore, btech mechanical engineering is solely based on basic classical mechanics or lower level classical mechanics, the majority of which is newtonian mechanics.
BSc physics is focused on quantum mechanics, and almost all areas of study in BSc physics use quantum mechanics like there isn't any newtonian mechanics in the universe, so whatever they would be thinking in India about degree equivalence, a BSc physics is way higher than a btech mechanical engineering in terms of theoretical knowledge and depth of physics and mathematics, in fact, a BSc physics is way higher than btech, So, if you get into one of those select few universities, you'll have to work extremely hard or you'll end up in hell. Also, if you want to study physics overseas, a btech is ineligible for an MSc or MS in physics. Only those with a BSc/BS in physics are eligible. As a result, you won't be able to pursue an MSc in another country because their qualifying standards only allow for BSc/BS physics.

You can do Masters in psychology being a B.Tech CSE graduate. It's quite easier to switch now to Masters psychology. Get ready to do hardwork since you are not a psychology background student. Few colleges won't allow non psychology background students, check before and join accordingly!
Without a bachelor's degree in psychology, you can pursue an MA or MSc in psychology. The eligibility requirements will differ from one university to the other. Many leading colleges provide an MA in Psychology to graduates with a 50 percent graduation rate. So, if you have a B.Tech with a grade point average of greater than 50%, you can apply.
Some colleges grant admission to courses based on their degree grades, while others grant admission based on their entrance exam rank. In addition to the written test, some universities will conduct an oral examination. Almost all major institutions offer this subject, which you may research on the university's website.

This job choice would waste a number of years of your life with little reward. If you get your B.Tech from a good college, you can get a nice job and if you want to study further then It would be a wise decision to choose LPU because, in the current scenario, this is the university that caters to the all-round growth of its students and nourishes them with care to propel their careers to a pinnacle of ultimate achievement that many would envy. LPU is one of the top 100 universities in the world, including IITs. LPU was also honored with the National Employability 2020 award for outstanding student employment. MNCs attract students to top jobs, and LPU has been awarded National Employability 2020 for Best Placements.
900 firms come to LPU for internships and on-the-job training, and 700+ companies hire LPU graduates for top jobs. Every year, around 550 companies come to campus to participate in such programmes and recruit students from LPU. According to my knowledge admissions are in process at the university check the dates for LPU NEST and eligibility criteria from the university website. All the best!

IT Managers have huge opportunities to work in IT domain of any big company or directly in technology firms. Indian IT giants like TCS, Infosys, WIPRO, Tech Mahindra, HCL Technologies etc. Hire MBA IT from top Indian B Schools for business development roles and offer an attractive entry level salary. Scope also depend upon which MBA school you pursue your MBA, LIST OF TOP PRIVATE MBA COLLEGES IN INDIA
Xavier School of Management, Jamshedpur. Lovely Professional University, Phagwara
Indian School of Business, Hyderabad. S. P. Jain Institute of Management and Research, Mumbai. Birla Institute of Management Technology, Greater Noida. Symbiosis School of Business Management, Pune.