You can prefer Arihant MCA Entrance book Amit M Agrawal, You can also prefer RS Aggarwal and objectives books by By J B Dixit, Ruchi Sharma, Ashish Mangal, If you are preparing for NIMCET Entrance Exam.

I would also suggest you to go through with the previous year papers to know the level of the questions, You can also check the syllabus & exam pattern with the given below link for NIMCET Entrance Exam.

https://it.careers360.com/exams/nimcet

Good Luck!