I wonder what modernization package the Russians are offering. In the ongoing ARMY expo in Russia they have apparently offered the Palash CIWS to replace the AK630s that the Navy uses in the entire fleet. 3 of the Talwars have the 630, other 3 use the Kashtan CIWS.
Obviously there would be the Shtil-1 VLS on offer replacing the old arm launchers. Maybe without the arm launchers missile count can be increased from 24 to 32. I don't think the Talwars have much space for more cruise missiles, unless you get rid of the RBUs. The main gun can be upgrade from 100mm to 130mm, won't make a huge difference though.
That's all that comes to mind really. The Talwars are already pretty well equipped. The Russians could offer Redut series SAMs instead of Shtil. I doubt the Navy would like to add yet another SAM to their collection. the Navy could be interested in better radars though.