what are the cources required after 12th to pursue my career as a astrobiologist?

hi,

see astrobiology is related with physics, chemistry,  biology, micro biology, ecology, planetary science, geography, geology , biotechnology etc. so fist of all you should take b.sc in any of the above discipline , than you can do masters course or diploma course on astrobiology. however there is very less opportunity in india and not very much institute available which provide courses on astrobiology. you may go for diploma program in astro biology in indian astrobiology research center. or you may opt for master course in foreign institutes.