The maximum score you can get from SINP, if you don't have an SK job offer of relative, is 80. The cutoff is usually in the range of 70-90, many times more than 80. And you can get a feel of what kind of ppl can actually score near 80 w/o job offer or relative.
I would say don't even think about it unless you are exceptional. But if you are, you will probably score highly in CRS too lol. So you see..