My dear Prathamesh..
At first congratulations that u have cleared ur 12 th examination..
Now,if u have Biology in ur subject..u can definitely write in NEET exam ..
Other wise , u can do B.pharm, BMLT, AYURVEDA, Homeopath....etc ..

Now , u can also go for Bachelor's degree..
U can do BSC ..then MSC and after that u also do ur PHD..

AFTER That, u can go with Engineering..there are 3 types of engineering..

1. Mechanical engineering
   
2. Software Engineering
   
3. Chemical engineering
   

Also u can go with .. ARCHITECTURE, BCA, BSC IN COMPUTER SCIENCE...ETC

THERE ARE MANY THINGS TO DO AFTER 12th..
but have to understand in which side u have interest ..then u can go for it ..

do, hard work ..and smart study ..

All the best dear!!
thank u..