listen to be honest, just listen to me and no one else here 
if u are indifferent between nikon and canon, tou go for canon abhi as u have limited budget and get a prime lens with the 18-135mm kit lens. get 550d or 600d doesnt matter. canon lenses are cheaper and u wont have a problem upgrading. 100k is enough for u currently as a canon user and will get u the stuff that will last ur hunger for 2 years. I said the same for nikon, but seeing u indifferent towards both brands, i would say buy it NOW, a Canon and dont delay it.
I being a Nikon fan would like u to also buy one and i too was faced between Nikon vs Canon i.e. D5100 vs 600D exactly a month ago, but i got D5100 because i just love Nikon. Simple 