In astrology his life is in the balance (6)
I believe the answer is:
libran
'in astrology his life is in' is the definition.
I know nothing about this answer so I can't judge whether this works.
'balance' is the wordplay.
I cannot quite understand how this works, but
'balance' could be 'libra' (the Scales in the zodiac) and 'libra' is present in the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'the' is the link.
Can you help me to learn more?
(Other definitions for libran that I've seen before include "in one House" , "Person born under Sign of the Scales" , "One born between a Virgo and a Scorpio" , "One born Sep 24 - Oct 22" .)