It is important to know which State's bonafide resident are you. This is important to identify your eligibility criteria. According to Tamilnadu MBBS Eligibility criteria mentioned in https://medicine.careers360.com/articles/tamil-nadu-mbbs-counselling , to claim Tamilnadu State domicile, you:

1. Should be a bonafide resident of Tamilnadu
2. Complete 6th to 12th in Schools of Tamilnadu. In such case, you will be considered under Open Category.

But you  studied only from 7th to 10th in Tamilnadu. So if you have to claim Tamilnadu's domicile, you should be a bonafide resident of Tamilnadu. On the other hand, if you look at AP eligibility criteria mentioned in our article: https://medicine.careers360.com/articles/ap-mbbs-application-form:

1. You should have studied in AP for atleast 4 years
2. Either of your parents should have resided in AP for atleast 10 years. So you should select AP as the State for State Counselling and not Tamilnadu.

To help you during admission and counselling, we have https://www.careers360.com/mbbs-companion.