Take the job. 3000 SGD is not a lot. U will probably spend 1.5-2 k to live in Singapore. But u still will have 1 k extra which is more than ur Indian salary. U will have to share a flat with other people. But considering that u r making 21000 Rs in India, its decently good. U will get exposure n experience n will be able to save more than what u r able to do in INDIA.

I am assuming u r SINGLE n not married. Otherwise, its gonna be pain.