〒 vs. [no unicode yet]

why did it take this long for the indian rupee to get a symbol? the rupee goes back centuries, while the tenge didn't exist until 1993 and it has had a symbol (〒) for almost three years (although no one in kazakhstan seems to use it). is getting a symbol hard for some reason? and if so, why was kazakhstan able to pull it off so much quicker than india?