Dear Aspirant

Yes, you can go for 12th again with foundation but you'll have to repeat all the subjects in addition to practical exams and other things too which will be very problematic. So, to avoid problems during 12th again, you have one more option to increase your marks by going through NIOS admission where you can take course named as "Senior Secondary Course-Equivalent to class XII" and you may take maximum four subjects for the same as per your choice.

Below is the link for NIOS where you may get to know the dates and procedure for admission

https://sdmis.nios.ac.in/

Hope this helps you.