The reservation of ews is a new one.According to central govermnet policy resevation amounts :

OBC-27% ,SC-15% ,ST-7.5% .In obc there are more seats available ,but in case of ews it is only 10% .More over , all students from general actegory below 8 lakh income,will get ews category.So there will be lots of students in this category.So obviously OBC reservation will get advantage.