Lend one thousand rupees to be invested by postman? (6)
I believe the answer is:
impart
'lend' is the definition.
(synonyms)
'one thousand rupees to be invested by postman?' is the wordplay.
'one' becomes 'i' (Roman numeral).
'thousand' becomes 'm' (Roman numeral for a thousand).
'rupees' becomes 'r' (abbreviation for rupees).
'to be invested by' is an insertion indicator (I've seen this in other clues).
'postman?' becomes 'pat' (children's TV character Postman Pat).
'r' inserted within 'pat' is 'part'.
'i'+'m'+'part'='IMPART'
(Other definitions for impart that I've seen before include "Reveal about armpit" , "Give, say information, make known" , "Share, pass on" , "Divulge, inform" , "Make known, relate" .)