Hi Guruvignesh
First of all, getting at a specified college cannot be easily determined by your rank it changes every year. But you could get a near accurate result based on the previous year results. For this you can make use of the Career360 college predictor.
Now, regarding your second query; the best college is Tamil Nadu are the IIT and NIT present for that you need to write the IIT JEE Mains and Advanced(getting good grades in Mains help you get into NIT and Advanced for IIT).
The college after this is VIT and for that you need to write the VITEEE. The admissions are solely based on the ranks in their exams.