Hi @Raaghuik1996
create new column with this expresion:
Iif(@column='January','1' , Iif(@column='February','2' ,Iif(@column='March','3' ,Iif(@column='April','4' ,Iif(@column='May','5' ,'Other')))))
Adjust source column name and other months.
In case you have dates in some column you can use built in function for month number Month (<Date>)
Regards,
Milan