Brother 

I faced the same situation 4 years back without going throug the exact details you need to get these things verified first 

1) they're talking about family income other than your dad's salary. This is most important I didn't check this during my 12 and applied for JEE as unreserved I got a good score and didn't get seat cos my score was less for oc I've cleared cutoff by 45 marks in obc 2015 but didn't no then so I suggest you to get throught exact details.