As of today's world, anyone can teach online after completing some basic graduation . Even on YouTube, some people who have just entered into an Undergraduate course, have started teaching their juniors, and able to earn via YouTube ADSense. So, for such online teaching, there is no specific degree required. Even platforms like Unacademy are inviting those (irrespective of your educational qualifications) to teach who have teaching as a passion. Plus since you have done BTech, you can easily teach Class 12 Students or Biology to NEET UG Aspirants.

However, the above mentioned online teaching, has cons as well - you cannot guarantee that you will get many students and you will be earning as per your needs. No doubt, some teachers have become famous by teaching online, but not everyone has been able to achieve the same.

So, I would suggest you to complete your masters (M.Tech) first. Crack GATE with a good rank and take admissions in good institute. After that you can easily get teaching jobs and would be able to teach B.Tech students as well (Remember: A B.Tech graduate cannot teach B.Tech students as per AICTE rule).

Yes you can teach Science to school students from class 5th to class 12th in School after completing your Bachelor of Technology in food technology or any other specialisation. You can also teach them in an open teaching institute. You can also open your own coaching institute for teaching science to school students.

However for teaching in college as a professor of Food Technology department you have to you complete your masters of Technology or PH D.  in the same specialisation. After then you will be considered eligible for applying in college for the post of Professor.

Read more details about to technology post by clicking on mentioned below link:

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.careers360.com/courses/food-technology-course&ved=2ahUKEwigotnAo5L1AhV54XMBHRiDAXEQFnoECAQQAQ&usg=AOvVaw19TszdAn79qKQUR1xZgHU4

Hello Swara,

A teacher is a skilled professional who imparts knowledge to students through academic study. Under the supervision of teachers, students learn through a curriculum that includes a variety of subjects and activities. Each subject has a specialised teacher who guides students through the learning process and grades them based on their academic performance

For employment as a Primary Teacher in a Government School, a Senior Secondary School Certificate or Intermediate or its equivalent, as well as a Bachelor of Elementary Education (B. El. Ed.), or Diploma or certificate in basic teachers' training of at least two years duration, are required.

Another general requirement for becoming a teacher is an Ed degree (Bachelor's of Education) with a minimum of 55 percent marks. The pass percentage required varies from school to school. Some colleges require a master's degree in the relevant discipline in addition to a B. Ed. to teach higher level classes.

Also check the link out:-

https://www.careers360.com/courses-certifications/articles/top-10-careers-options-after-completing-food-technology-course

Hope this helps!