Need help about MS in Chemical/ Petrochemical

Dear Sir/madam,

I am Vetrivel from Tamil Nadu. I have completed B.Tech in petrochemical Technology in Anna University Tiruchirappalli, Tamil Nadu, India. I like to do my M.S or M.Tech in the Field of Petrochemical/ Petroleum Refinery or Chemical Technology with scholarship. I am working in Madras Fertilizer Limited as Graduate Apprentice. As the same time I have planned to prepare for GRE. Is my Apprentice exposure eligible for experience or not? Just now I am begins for preparing. How much mark should I take in GRE for M.S in Chemical/ Petrochemical Technology? Can you guide me someone?