MCA Entrance Exam

I think you should opt for B.Tech only if you are getting a good college. Otherwise, go for MCA through NIMCET.

1. MCA entrance examination book of Pune University
written by J.V. Subramanyam,
2. TANCET MCA-Anna University
written by V.V.K. Subburaj,
3. IGNOU openment Entrance Exam for M.B.A and M.C.A
written by V.V.K. Subburaj, etc.

Basically the questions of MCA entrance examination are similar to BCA 1st and 2nd year maths paper. So collect year solution of BCA 1st and 2nd year Math paper and practice and do some basic programming basically C, C+ and Java.

Syllabus of MCA degree Entrance Examinations varies in different universities. Syllabus generally includes following:
(I) Basic Mathematics
(ii) English Language & Comprehension
(iii) Computer Awareness
(iv) Logical and Analytical Ability
You are advised to do self-preparations on computer awareness to crack any MCA entrance examination.

Dear,
It is always advisable to take the support of coaching centre for better and methodical practice.

There is no specific guide for OJEE(MCA). This exam carries 4 general part (English math reasoning and verbal ~non verbal abilities). You can be successful as per your level best.
Good luck.