Russia should look at some creative ways to win orders from India for Mig-35. India has been having maintenence problems with the Mig-29's. Maybe Russia can offer to exchange the current Mig-29's India has for Mig-35 with Thrust Vectoring(India can pay the difference in cost). Like someone said earlier India is looking to standardize its platforms the the different Migs only makes it difficult for IAF. Once the Mig-35's comes in, it is always easier for the client to order more of them. Also Mig-35's operating in India makes it easier for more orders from other clients.
Like in the case of Su-30MKI the orders started small but it has become a huge order now. Also Sukhoi's decision to replace the Su-30K's and Su-30MK-1's with the Su-30MKI's made it easier to win support in India and easier to order the 40 more.
Russia can pull a trick out of the bag and this option is not there for the other competitors.