50-60 per cent is a reasonably high mark; one of the best and related options in a similar discipline is to go into some form of university computer course.
Computer courses provide you with a relevant career for the future, especially in India where large amounts of investment from companies is computer orientated. You can also do one of the many Masters courses in computers afterwards if you want to further yourself in a more specific area.
There are also plenty of science disciplines to choose from for the biotech side of education to more chemistry and physics orientated degrees. All of these are good options for the future in an ever more science leaning society.
If you wish to take the vocational route and take part in occupational therapy, physiotherapy, nursing, computers or a form of management, science leaves a person open to a wide array of things to do. Plenty of these courses want people who have strong biology backgrounds.
Teaching or doing a B.ED is also an option at this level. You can learn to teach science or primary education to children if you follow up with an education degree.
Or perhaps you want to do something that is not related. There are many options to do things in anything from business to fashion to industry afterwards as well as get a job in a workplace where you can hope to get down to labor and earn money also.
Whatever your choice there are many options available to those who take 12th Science.