Souscrire belong to the 3
rd group. Souscrire is a common french verb.
Souscrire is conjugated the same way that verbs that end in :
-ire
Souscrire is conjugated with
auxiliary avoir.
Souscrire verb is
direct transitive, indirect transitive, intransitive.
Souscrire verb is a direct transitive verb, so passive voice can be used.