Hi Madhuri. As a recent MBA HR graduate (with 2 years of work experience in a non-HR field), I can safely say that an MBA in HR or any other field is not and never was an absolute necessity.
People, especially from technical fields, generally find that they may not have the necessary skills to work effectively on the job, such as people skills, leadership, and communication. An MBA degree, in my opinion, helps build upon these skills. Hence, you have to look at your motivation behind doing an MBA. Is it purely monetary, knowledge-driven (which happens on your own in B-Schools - no spoon-feeding!), or as an escape (from your job, parents nagging for marriage, and so on. Sorry for being so presumptuous).
Another point is the mushrooming of MBA colleges in India. We can see that even Tier I colleges like IMT and SP Jain have also succumbed to the monetary gains and have increased their batch sizes, resulting in a large pool of MBAs that are not capable and thereby not employable. There are also other Tier 2 and 3 colleges acting like factories. As a result, an MBA (in any vertical) from only top-notch institutes has that absolute high value. Others are just also-rans. (I'd clarify here that I am NOT from a top-notch MBA B-school)
You have already mentioned that you have 14 months of HR experience, which is quite a decent time in HR. By now, you may be able to figure out different aspects of HR and which areas interest you. Build on that, read different books not only on HR but also on management in general, and become a very strong HR person.
If, despite all this, you feel the urge to do an MBA, you can do so over 2 years or more. Start by sticking to your job and giving all the MBA entrance exams this year. You will understand your strengths and weaknesses. Try again next year and so on. I am not able to elaborate on more points because of a lack of time.
Hope this has been of little help - if any.