I think you are completely off the mark this time
1. Talks with Russia to reduce RCS of the Su 30 in 2012- 16 never materialised because in IAF's view the RCS reduction is not worth the money spent (Russians quoted a very cost)
2. Indian govt and IAF have categorically refused to go to Russia for any sort of upgrade for it's jets, citing reasons such as
• Russians charging exorbitant prices
• Indian MIC having the capability to do the upgrade themselves
• Indian upgrade being better than the Russian one due to us having access to western subsystems (primarily Israeli)
3. If IAF ever decides to go for RCS reduction measures (and this is a big if) it will not be Russian for sure, India has developed all sorts of RCS reducing materials and we can do it ourselves
Take this for example