Having done a B.Tech in Aeronautical Engineering, you have several options for further studies. You may do an M.Tech or MS in advanced areas like Aerospace Engineering, Avionics, or Aerodynamics. GATE is mandatory for M.Tech in India, and GRE and TOEFL/IELTS for foreign studies. Several Indian universities (IISc, IITs, NITs) and international universities (MIT, Stanford, TU Delft) offer postgraduate programs.
Alternatively, if you wish to transition into management or business, an MBA in Aviation Management or Operations is a good option. Research opportunities also exist through PhDs in aerospace technology, drone systems, and propulsion. DRDO, ISRO, NASA, and DAAD scholarships and fellowships finance studies. Higher education increases career opportunities in research organizations, aviation firms, and space agencies globally.