You can easily import OLM file to Gmail using Third-party software like  KDETools OLM Converter. Software is a unique method for recovery damaged OLM files and also convert OLM to Gmail account. The Software also supports multiple files formats such as- Gmail, Zimbra, PST, Office 365, Live Exchange server, MBOX, vCard, vCal, EML, EMLX, MSG, PDF, NSF and etc.