Hello Student

You  cannot claim reservation for your son for the state of Karnataka because in Karnataka  there is no approval of your caste as ST in the government notification on gazette. So you have to apply for Neet exam if you want to avail the reservation opportunity, then it will be better for you to apply for the state of Tamilnadu in which state your cast is approved as ST cast in government gezett.

Only the central reservation policy applicable for the central job and education only.

A 5 bench judges of Delhi High Court give the verdict that the candidate belongs to which state that approves his caste , that only e n joy the reservation opportunities for the specific cast in specific state.

Hope this helps.