Well if the russians don't take India's concerns,then it is Russia which loses. India will simply switch sources as time goes on.
Now if this is seen as a major breakthrough for Pakistan,sadly that may not be the case.
Unfortunately India as one of the world largest importer of western arms would be much more powerful than one of the world's largest importer of Russian arms.
In such a case..China would be facing a far too formidable foe on the western border..just because it wanted to increase it's imports by using Russia system.
It is China and Pakistan that have source and budget constraint respectively. India may have budget constrains but not the source!
How do you people come out with these fairly tale? China is the biggest buyer of Russian arms more than India, Russia can switch and sell else where to make up the cost if it looses India, since India is moving some what towards west (even at this point) what makes you think Russia will stay loyal to Indian demands? They have their own interests as well you know, loosing India isn't going to crash the Russian arms industry. They may not have that much money, but loosing India they can open more JV's with China, since they already recieved help with J-10 from Russia (it's shows they dont care and follow where the major money is).
Also, note they are soon going to break into the ME market where, KSA and others willn't put their money all in one basket.
Now if this is seen as a major breakthrough for Pakistan,sadly that may not be the case.
If India switches sources, what makes you think Russia will listen to you, if it starts supplying Pakistan, we already seen what happened with RD-93.