Give one's assent to tour India with Mr Hunter (6)
I believe the answer is:
nimrod
'hunter' is the definition.
(I know that Nimrod is a hunter)
'give one's assent to tour india with mr' is the wordplay.
'give one's assent' becomes 'nod' (I can't justify this - if you can you should give a lot more credence to this answer).
'to tour' is an insertion indicator (to tour can mean to go around).
'india' becomes 'i' (phonetic alphabet: alpha, bravo, charlie etc.).
'with' means one lot of letters go next to another.
'i'+'mr'='imr'
'nod' going around 'imr' is 'NIMROD'.
Can you help me to learn more?
(Other definitions for nimrod that I've seen before include "Might hunter of Genesis" , "Skilful hunter (Genesis)" , "'Mighty Biblical ruler, builder of the Tower of Babel (6)'" , "One of Elgar's Enigma Variations" , "Best-known of Elgar's Enigma Variations" .)