Hey !
Bachelor of Science in Nursing(Bsc Nursing ) is a 4-year undergraduate course.The minimum eligibility criteria for Studying this course is the successful completion of 10+2 level of education in Physics, Chemistry, and Biology.The average course fee ranges from INR 8,000 to 30,000 per year.
Many colleges in India offer this course as a branch of medicine. Admission is done on the basis of the entrance exam conducted. Generally it is between the months April and June. Check the below link for information regarding Bsc nursing at one of the top college (AIIMS)
https://www.careers360.com/university/all-india-institute-of-medical-sciences-bhubaneswar/bsc-nursing-hons-course
Hope this helps
All the best !