A fleet tanker/replenishment ship. Supply resources (fuel, food, ammo etc) to your warships when they are out in the high seas to extend the time they can be out there without needing to return to base etc. There is a picture of existing one in the link.
The WW2 Pacific war has the most details concerning them w.r.t stories you can look up regarding their importance and following their respective warship flotillas etc.
The proposed FSS class (built at HSL from TAIS tech transfer) would have been bigger and something along lines found in pic here:
A spokesman of the Indian Ministry of Defence announced back in March that Hindustan Shipyard Limited (HSL, Visakhapatnam), India's state-owned shipyard, had signed a contract with TAIS, a consortium of five Turkish shipyards, to design and build five large Fleet Support Vessel (FSV) with a...
www.navalnews.com
Covid put a real spanner in the works on top of already not great situation to move this project forward.
It is imperative that Turkiye stabilises and improves its economy and not substitute talk + shortcuts to make up for it (while doing destructive economy policy to itself).
With the relations as bad state as they are in with PRC for example, India still works to improve what is needed when the larger economic basis is concerned:
https://economictimes.indiatimes.co...sector-on-the-cards/articleshow/101882976.cms
So Turkiye ought to form this basis now as priority and relations then will achieve size to improve organically when political windows and such arrive later as they do (by extension of this or new opportunities).
Turkiye is in great position w.r.t its location with EU (and customs union it enjoys with it) and this will form a huge basis for steady relations with India to provide a lot of components on pricepoint it can in supply chains Turkiye hosts and is attractive for EU market....benefitting all parties economies especially as more countries want to reduce dependence on PRC.
It increases opportunities for people people interaction and exchanges like say Yirtik Pantolon vlogging of his India visit (and he showed good and bad sides of India, and it spurred lot of interest.....he even hitchhiked in Kashmir of all places). That is most important thing, regular joe stuff expanding and then it molds environment for what political executives can and cant do longer term in better way for both sides.
Even on political exec side, Erdogan admin has made solid overtures in quieter meaningful way (past what gains most attention)...he sent first rate ambassador (Firat Sunel), lot of good things happened relationship wise after the earthquake tragedy, trade delegation meetings etc have been quite positive....so the trajectory can keep improving let us see.
Defence exports, cooperation etc is just a final apex tier thing that needs the bedrock and middle layers to be sound and robust and that should be prioritized for now to grow trust over time.