Shantanu,
So; to summarize:
1. It seems you currently have some experience as an SAP end user of some kind
2. It seems you have some college education not directly related to SAP software
3. It seems you are toying with the idea of being a consultant for SAP software. Or something.....
Can I learn SAP HANA as a fresher ?
Yes, of course. People are doing this every day. Everyone starts somewhere.
...or should I go for SAP BI with HANA ?
This option is also viable. Obviously a larger scope.
What are the pre-requisites to learn SAP HANA ?
At least average intelligence and a willingness to learn. If you look at the SAP course https://training.sap.com/shop/course/ha900-sap-hana-live-classroom-008-in-en/ you will see that they don't really require much prerequisite knowledge; they only require a fat pocketbook.
Due to financial constraints it is not possible for me to leave the job,so I want to know whether SAP MM end user can become SAP HANA consultant in the future ?
Of course. As mentioned by expert Jürgen, careers are typically open to any candidate who is willing to put the work in to study and learn. One notable exception is being an heir to a large family fortune. I have been searching for the course material for that career for the past 40 years, but I have been unsuccessful.
SAP HANA will be implemented in my organization in the year 2017.So what would you advice me on that ?
Wait patiently. There is very little you can do that will have an influence on the arrival of 2017.
....take experience of SAP MM ? or quit the job....
??? I thought you already excluded the option of quitting.....
and look for SAP BI course and job ?
As I said before, a viable option. You probably will want to make up your mind before you start your training. .
SAP PP,MM,FICO end user experience for 1.5 yrs and then part of SAP HANA implementation in 2017. Will it be a good idea ?
If your goal is to become some type of consultant (and I am not entirely sure what your goal really is), user experience alone will not prepare you for a career in consulting. However, people who are properly motivated can learn 'consulting-type' subject matter, through self teaching; through courses, and through interacting with local subject matter experts. This ongoing educational process can take place at the same time one is holding down a 'day job' as a user. Many companies also will financially support career-based education.
Best Regards & Good Luck,
DB49