India is too big to be worried about sanctions. Sanctions did jack shit in 98 with a much smaller economy and they will do nothing now.
Actually, India is resource deficient to some extent. India can survive sanctions. But, due to hopeless ancestors, India is lagging behind in technology which will need excess resources to be developed quickly. If India had 100% indigenous defence manufacturing and technology, then sanctions can't do anything. But, with existing poor state of affairs, first thing to do is indigenisation of defence. Later, testing can follow.
No testing till defence is fully indigenous. We need technology like SCALP missiles, meteor BVR, israeli BARAK-8 seekers, radars and Kaveri engine consultancy (and F404/F414 for time being) for reverse engineering or filling the gap