Dear Dileep, some of the books recommended by experts for MCA entrance preparation -

• Master of Computer Application Entrance Exam by R.Gupta
• MCA Entrance of All India Universities by GKP
• The Pearson Guide to MCA Entrance Examinations by Edgar Thorpe, Showick Thorpe.
• A Complete Study Package for MCA Entrances by Amit M Aggarwal

Also one more thing to note is the MCA entrance exam doesn't have a uniform pattern as in case of JEE, PMT, CAT etc. i.e. It is more of University specific i.e. different universities follow different pattern. Hence my advice would be to first thoroughly go through all previous year questions paper of the universities you are eying for.

Most of the questions in MCA entrance exams are repeated from previous years.

All the best.

Feel free to ask for any query.