Hello subrat, congratulations on your good marks, You do have lot of option for doing carrer after 12th , if you intrested in science subjects then you can go for engineering or do if you are interested in computers then u can apply for doing bsc or bba- ca which is a new introduced course before named as bca.. if you are intrested in management then you can apply for bba ie: bachelor in business administration which is probably the best course for doing carrer in management.. also there are very different fields in which you are intrested in.. as you have good marks its advantage to get a good college too.. 

all the best