I am a little confused as to the difference between the two as well as, if i do MBBS in india and then go abroad for MD will i have to repeat all 6 years or what year can i join from
if you graduate with a degree in MBBS you will start as a foundation year 1 doctor, whilst if you graduate with an MD you start as a foundation year 2 doctor. you can do a postgraduate course for your MD degree after attaining your MBBS which may last 2-3 years or you could just start practicing as a trainee doctor.
I am a little confused as to the difference between the two as well as, if i do MBBS in india and then go abroad for MD will i have to repeat all 6 years or what year can i join from
There's no point in gaining two primary medical qualifications realistically. In some countries the primary medical qualification is the MBBS (e.g. in the UK) and in some its the MD (e.g. in the US).
Note though that in countries where the MBBS is the primary medical qualification, there may also be an MD qualification which is a separate qualification unrelated to the US or similar format of the primary medical qualification being the MD. Such as the UK where the MD (often stylised as MD(Res)) is a research degree similar in some respects to a PhD (I believe usually shorter and only advised rather than supervised though).
You shouldn't be pursuing these qualifications with the aim of adding letters to your name, you should be pursuing them for the purpose of following a particular career. So do what is necessary for the career and forget about anything outside of that.