New pupils confusing tea with ink (6)
I believe the answer is:
intake
'new pupils' is the definition.
(I've seen this before)
'confusing tea with ink' is the wordplay.
'confusing' is an anagram indicator.
'with' says to put letters next to each other.
'tea' put after 'ink' is 'inktea'.
'inktea' is an anagram of 'INTAKE'.
(Other definitions for intake that I've seen before include "Body of new pupils" , "Consumption" , "Group of new pupils in a school" , "(Quantity of) new students accepted by school" , "Number of people or things accepted or received" .)