Hi Lishika,

On JEE Mains rank of 401618 and ST rank of 8816 it is difficult to get seat in any top NIT. Generally in order to get seat in any top NIT under ST category the rank should be below 2000 respectively. But you may get some of the average NIT with any random branch . Also it is difficult to get IIIT and GFIT from mentioned rank .You can check this in details branchwise NIT , IIIT, GFTI's cutoff rank from below link :

https://engineering.careers360.com/articles/jee-main-cutoff

All the best !!