Lizard in India and South American country? Not unknown (6)
I believe the answer is:
iguana
'lizard' is the definition.
(I know that iguana is a type of iguanid)
'india and south american country? not unknown' is the wordplay.
'india' becomes 'i' (phonetic alphabet: alpha, bravo, charlie etc.).
'and' means one lot of letters go next to another.
'south american country?' becomes 'Guyana' (country in South America).
'not' indicates named letters should be taken away.
'unknown' becomes 'y' (algebra).
'guyana' with 'y' taken away is 'guana'.
'i'+'guana'='IGUANA'
'in' is the link.
(Other definitions for iguana that I've seen before include "Type of lizard" , "cold-blooded customer!" , "Large lizard found in Guiana" , "Large crested lizard" , "The Night of the ---, (T. Williams)" .)