Hello !!

To prepare for NIMCET i suggest you to with RS Agarwal,A complete study package for MCA entrances by Amit M agarwal,objectives books and arihant publications  by By J B Dixit,Ruchi sharma .And..You better go through the previous papers and do practice so that you can get to know the pattern of the question paper and take mocks you will get to know where you are .To find the syllabus of NIMCET 2020 just go through the link provided below and it provides you section wise syllabus.

https://it.careers360.com/articles/nimcet-syllabus

All the best for your exam!!!