Pay, unfortunately, has to be raised on railway (6)
I believe the answer is:
salary
'pay unfortunately' is the definition.
'salary' can be an answer for 'pay' (thesaurus). I am not sure about the 'unfortunately' bit.
'has to be raised on railway' is the wordplay.
'has to' becomes 'alas' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'be raised' is a reversal indicator.
'on' says to put letters next to each other.
'railway' becomes 'ry' (abbreviation for railway).
'alas' backwards is 'sala'.
'sala'+'ry'='SALARY'
Can you help me to learn more?
(Other definitions for salary that I've seen before include "Worker's pay" , "payment only for non-manual workers" , "(Employee's) pay" , "Remuneration for Ray and Sal" , "Annual pay" .)