The Indian Rupee is all set to get a New Symbol. The above designs have been shortlisted. Great to know that we are going to get our Currency Symbol. Just like Dollar has $, Pound has £, Euro has € etc.
All above symbols represent R of Devnagri (Hindi) Language means  ” र ” (Ra)… Option 1 is so childish. How did it make to the final 5 is amazing.
There is no regulation for Currency Symbol selection. It should be compatible as per all views like Language, International presentation and uniformity.
My view is that instead of promoting the letter “R” for Rupee , we could have tried to promote / represent the country as a concept. (Eg: the letter “I” for India , or “R” for Republic of India etc.)  By looking at Dollar has $ — like “S” for States, Pound has £ — like “L” for London , Euro has € — ‘E’ for European Countries….
And lastly none of the above symbols appeal to me…..