You only reserve the right to call something indigenous when you develop the product from the scratch including designing which is the core of SAM systems as the designs and other specs are copy righted under international law unless a transfer of technology agreement or license production agreement is signed.
Performing a sensor upgrade on a russian system won't make it "indigenous".
If we claim the missile developed by ourselves after years of development and trials that is burning you because you cannot do it yourself? Do you know what is called sensor upgrade and what is there in the missile? No, you do not bother about it.
Suddenly came into mind, "ohhh there is a Indian missile looks like Russian, let me post it and make some fun," but you do not know it will backfire.



You again proved yourself!! You do not deserve a reply, because you do not know it neither you understand them. "No matter what inside and how much they are different but this cannot be Indian, how it can be!!!!" lol