So I have noticed in my Black that about every 3300 wild Pokemon encounters, I meet a shiny Pokemon. I have been keeping tabs on this for a while and I got one at 3310, (duh) then I got one around 6620, then 9930, now I am almost at 13240 encounters, and I think it will confirm my theory. But I am wondering if the RNG(random number generator) is a fixed number or actually random in Black/White?

No. The RNG is not broke. Your RNG isn't a set number it is a COMPLETELY random number. For example:

You first encounter a shiny after 10 encounters but then next time you encounter a shiny (if you are lucky enough) you encounter it after 213685 encounters. Then the next time you encounter a shiny it could be after 1 encounter.

Ok that is enough. So inconclusion, No, your RNG isn't broken, you just seem to be very unlucky with your Shiny encounter rate is going up.