data scientists after 12 or after engineering

Data Scientist is a course that requires you to have atleast a Master's degree. You need to have a Bachelor's degree in Computer Science or Social Sciences or Physical Sciences or Statistics. So there is no specific stream for you to study to become a Data Scientist. You need to be able to analyse large amount of data and provide actionable plans. In short a Data Scientist is someone who experiments with data and understand millions of bytes of Data. So after your 12th, you can pick any of the courses mentioned above fields. But the recommended courses are:

Computer Engineering

Bachelors in Mathematics, Statistics and Economics

Bachelors in Computer Applications