It would make sense for VKS but only if price is right and MiGs they are getting are absolutely latest and the greatest. Otherwise they should stick with Su30
The MiG-35 is rather more sophisticated than any model Su-30... it does not have their range or payload but in many cases that extra range and payload is not needed.
You might use the extra range for 1% of missions, and with inflight refuelling not even that... and more importantly no aircraft operates with anything like max payload except in bombing missions perhaps, but even then with jammers and external fuel tanks and AAMs for self defence few will carry anything like their max payload.
In WWII an aircraft might carry its max capacity of dumb bombs but even better results can be achieved these days with 1-2 guided bombs so there is little need for your fighters to haul around max payload weights of dumb bombs.
Probably India may stick with Su. Su has better payload and range, and it can carry bigger, more powerful avionics and radar. Radars like Bars or Irbis is powerful enough at the moment (the West has nothing better than them), and its not like India need an AESA nose mounted radar at least for the next 10 years.
Traditionally, it is Su who has been designed to be the powerful and advanced, while MiG is cheap/massive alternatives (except MiG-25/31).
If India is really serious about diversity of war material then having MiGs makes a lot of sense.
A MiG-29SMT or their UPG variants are capability of multirole use with guided weapons... you don't need a 10 foot wide AESA to drop laser guided bombs, and for most targets you don't need to fly 3,000km to the target area and back.
Smaller lighter cheaper fighters make sense.
but Mig contracts are rather rare these last years.
That is an important thing to keep in mind... we are not just talking MiG vs Sukhoi... each company has other companies they deal with... so Saturn works with Sukhoi (AL-31s et al) and Klimov works with MiG (RD-33), and it is the same with radars and sensors and other components, so when MiG succeeds it means other companies also keep alive and earn money to further their products and upgrade their tools and production capacity and buy new design tools etc etc.
Neglect MiG and you will have no choice in 10 years time.
Fortunately it seems the MiG-41 will be funded, and of course the potential for a light 5th gen fighter from MiG is also on the cards if not totally certain...