Why "Admiral of the Fleet" rank ever given to any naval officer ?

[Lions Of Punjab]

what is the criteria of allocating the highest ranks like field marshall etc ? Even after successfull participation of IN in 1971 war why navy lacks an "Admiral of the fleet" ?

 

[W.G.Ewald]

what is the criteria of allocating the highest ranks like field marshall etc ? Even after successfull participation of IN in 1971 war why navy lacks an "Admiral of the fleet" ?

Won't see those ranks in peacetime, command structure doesn't require them. That's my guess.