You can say both of them but " Ishan" is much more formal than " Anha". Honestly we have 3 ways of saying " THEY" in Farsi: - " Ishan" ایشان which is very formal" - " Anha" آنهاnormal way of saying THEY - " oona" اونا which is very colloquial Look at the sentences below: آنها را دیدم./ Anha ra didam.= I saw them. اونا رو دیدم. / oona ro didam. = I saw them. ایشان را دیدم./ Isgan ra didam. in all the above sentences " Anha" is an OBJECT. Now look when it is a SUBJECT. آنها رفتند./ Anha raftand.= They went. اونا رفتن. / oona raftan. = They went. ایشان رفتند./ Isgan ra raftand. They went. Hope this will help you my friend. :)

hi Anha is slang form of Ishan but"'ouna"(اونا) is slanger than both of them!!!

Aanha

hny anha is comment but ishan is very formal for example if you want to write a letter to a company they use ishan but to a friend we use anha and in a conversation we use onha.But both have the same meaning

Anha , آنها