Bridge won't be a wise decision as u will miss a good DSLR like Nikon D3100 by only Rs. 10-12K.
The latest models of these series must be touching or over 40K in Pakistan.
Its not that Canon 1100D is bad. Its very good DSLR for starters but when u talk about the best in the category then Nikon D3100 is at the top right now. But Canon 1100D will not disappoint you at all infact you would be really happy
If you can find Canon 1100D cheaper than Nikon and it suits your budget then go for it.
Its all about money ........