Choose the latest version and if not choose 1.6 because in technology space its better to keep yourself updated. as you are doing MCA I am not sure how much programming you are doing but its always good idea to write small program to test various java feature and play with them along side theory and mock exam
Many roads lead to the Java SE 6 Programmer Certification. It all depends on your way of learning, the money and the time you have to spend to study for the exam. For me, the best way (and the fastest) is to buy a good book (K&B for example), however, there are heaps of fantastic resources available on google (search for java mock exams).
Also, make sure you know the objectives of the exam (from the oracle site) and cover them all, this is very important.
Finally, practice a lot and do not hesitate to ask a question in the Java forums if you don’t understand something.
i am doing programming as well as study because i want to get it clear within limited time of my course.
thank you for your sayings that know i am motivated to move to latest exam to give in few coming days