We need to follow below steps to migrate a Site Collection from SharePoint 2010 to SharePoint 2013:-
1. Backup and Restore SharePoint 2010 Content database in your SharePoint 2013 farm.
2. Run Test-SPContentDatabase cmdlet to identify missing Components along with potential errors and related warnings. Check the upgrade log and deploy any missing components and re-run the cmdlet to verify.
3. Attach the Content database to the desired web application using Mount-SPContentDatabase cmdlet.
4. After successfully mounting the content database to web application, the site should be accessible in 14 mode.
5. Next, to Upgrade the site to 15 Hive, Navigate to SiteUpgrade.aspx page in Site Setting of your site collection.
6. Click on "Upgrade the Site Collection" button.
7. During the upgrade The SiteUpgrade.aspx page shows the progress and provides a link to an upgrade log for troubleshooting purposes.
8. Site Collection Should now be accessible in 15 mode.