Calculate EMI based on principal, rate, duration (month or years)
In the comments to your other questions some things were mentioned that are also applicable to this question as well, like:


Try to follow PEP 8 style guide.
Single letter names should be avoided.
Avoid useless comments, make your code self explanatory.
Check for invalid input, raise exceptions.


Now, you have some magic numbers like 12, 100 and 4. Give them names. Make them constants. Don't leave them like that.  

Some prints don't make a lot of sense, like printing type of R or printing if duration is in years or in months. That looks more like information for debugging. I suggest you to take a look at logging module and give it a try. But for such a small program it is probably an overkill.  

This n = d[0:(len(d)-1)] is repeated twice in your code and it can be taken out of that if-elif statement. Moreover it can be simplified as n = d[:-1]. 

Instead of writing  

EMI = x*(P*r*(1+r)**m)//((1+r)**m - 1)
return EMI


you can write just

return x*(P*r*(1+r)**m)//((1+r)**m - 1)


Finally, wrap your print EMI_calculator(10000,12,'Q','3Y') like this:

if __name__ == '__main__':
    print EMI_calculator(10000, 12, 'Q', '3Y')


You can read about it here.