Hi I have a SharePoint Farm Solution developed in SharePoint 2010, We have a requirement to migrate it from SharePoint 2010 to office 365. Is it possible to migrate it without any difficulty or it is not recommended to migrate SharePoint 2010 to Office 365.
You can not directly use the farm solution in office 365, as Farm solutions are not supported in office 365/SharePoint Online. Please see this reference link: https://community.office365.com/en-us/f/156/t/232435
You will have to transform the farm solution in app model and then you will get the same functionality in office 365.
Click Here to see more about the transformation of Farm solutions to App Model.
Note: It's not mandatory that you use Apps only for this. You can use other approaches as well i.e. JSOM, OOTB etc.. It depends on the functionality of your farm solution.