Hi bikash, 

You have scored a good rank in aiims. Yes you have the chance of getting a aiims college . 

There are 1207 seats in aiims. We can't say that all the students having rank above you will prefer aiims it can be some don't. 

Last year aiims patna last rank was 1222 for general ,aiims raipur 1154for general, aiims guntur 1353 for general. 

Go for the counselling process of aiims till last round. Hope for the best . 

For any other query you can ask us