Variation on Indian 1 Rupee from 1969

I recently obtained 2 of these Indian 1 Rupee from 1969 commemorating Gandhi’s birth centenary (N#203803)

My question comes with the two variations. What is the difference between a large prefix or small prefix, the size or the letter starting the prefix

Any help would be appreciate, Thank you

It's a pity that they do not have the two varieties here to show you the differences. Perhaps do a search on eBay and see if you can find the other note to compare with. Good luck.