See if you are talking about taking admission in any college or any examination or any purpose in general regarding your academics or career then yeah! Voter card and the Aadhar card is one of the proof that you are an Indian Nationality. Although there are controversy regarding the CAA which says that having a mere card don't insure your citizenship or nationality. As CAA is not applied till now, you can undoubtedly use the Aadhar or Voter card as a proof of being an Indian National.

I hope this answer helps. All the very best for your future endeavors!