You have to check what are your requirement, what kind of search hybrid solution you need. Currently SharePoint hybrid solutions: Search, Business Connectivity Services (BCS), and Duet Enterprise Online.
In search you have to decide which topolgy you need.
SharePoint Server 2013 Search services can query the SharePoint Online search index and return federated results to SharePoint Server 2013 Search.
SharePoint Online Search services can query the SharePoint Server 2013 search index and return federated results to SharePoint Online Search.
Both SharePoint Server 2013 and SharePoint Online Search services can query the search index in the other environment and return federated results.
You can learn more about it: Overview of hybrid SharePoint 2013 for technical decision makers
You should also try SharePoint 2016 beta 2, MSFT announced a better hybrid solution in this version.