Hello Rushing,

AIIMS conduct entrance exam for  B.Sc nursing every year. There are two courses you can apply for - B.Sc (Post basic)  and B. Sc (Hons) 

Pattern for both are different. For B.Sc (basic) it is objective based 70 marks written exam followed with 30 marks interview 

For B.Sc(hons) it is 100 marks objective based written exam. 

One require sound knowledge of physics,chemistry,biology and general awareness to clear the exam. Physics, Chemistry, Biology can be prepared from ncert books. One can also prepare from publications like arihant which covers syllabus of nursing exam. 

Good luck!