regarding use of cast certificate in jobs

Sir my cousin who father is brahmin of low grade married to my aunt sc caste,cousin is issued sc caste for btech mtech study in telangana state and onthe background their father works as preist and works in hotel as supervisor and as agent for chit fund which may be enough for living,again issued low income certificate and has tv fridge washing mc computer sewing mc ;but contrary to my family my father bc and mother sc never got aid to me and my two sister from government,I want to ask is my cousin doing right for study should she get sc certificate to approach through state government job even if using her father name and using mother certificate.one thing againshe has a abnormal brother for which government gives 1500 rs /mnth,whereas my father is spoindilitis patient serving as fitter in private company getting 16000/mnth of which large goes to his medicine consulting treatment and left over to we three without being our bc certificate being supported to eligible in other state institutional bodies denying to accept to provide scholarship and other benefits,justify us what is right and wrong.