Group 1 verbs that end with 「る」 will have the form of 「って」while group 2 verbs ending with 「る」will have the form 「て」
As a general rule, verbs that end with "~iru" or "~eru" are group 2 verbs and will end with 「て」
However, be careful, there are exceptions, some verbs ending with "~iru" or "~eru" can be group 1 verbs (such as 帰る (kaeru))