Nursing is really a good career option and if you have the inclination towards 'service to people', then definitely this is a great field to work in.
However, I am worried looking at the percentage. Since you had taken Science and still you could manage 43% in 12th is a great matter of concern. What is the reason for such low percentage in a scoring stream?
You need to sit for class improvement and score minimum 50% or forget about Nursing course.
I would suggest you to take the Ideal Career Test from Careerguide.com
This is a psychometric test and will help you know yours