Hello Sahil, 
Cracking GATE Exam do not get you to MNC (Multi National Companies)  but cracking GATE will definatly open doors to several PSUs (Public Sector Undertakings) like NTPC limited, BHEL, GAIL, BPCL, Hindustan Petroleum Corporation Limited, Oil and Natural Gas Corporation Limited etc.
And the benefit of getting into one includes
high paid salary
extra incentives/allowances.

Hello Sahil,

You can get a great job in good psu's after you clear the gate with good rank <500.

But to get into PSU'S  like ongc,iocl,bhel you have to secure a very good rank in gate under 150 or may vary it completely depends on the vacancies of the MNC'S.

You can check for the vacancies on the official site of mnc's.

All the best for you career.

If you any further doubt ask about it.