hi,

well it is possible , but you have to again repeat 11th and 12th course, which means two more years of studies. the eligibility criteria to become eligible to apply for science in 10+2 course, candidates must complete 10th standard exam with mathematics and science. the marks criteria may differ college wise. however you may also apply for nations institute of open schooling. by giving nis on demand exam you may complete 12th course in one year, but to better understanding it is necessary to complete 11th and 12th. follow the below link to know in details about nios, or you may directly go to nearest nios study center

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