Hi
You can write a Java service (OSGI service) which reads your XML data and using JCR API's you can create corresponding nodes (with all data and properties) inside CRX repository to persist it. Once you have all the data - you can read this anywhere on your pages(websites, widgets, etc). Generally use XSLT to convert from one format to other.
Please have look at this post:- http://stackoverflow.com/a/31435442/6433590
// AEM6. XML import to JCR
Reference article :-https://helpx.adobe.com/experience-manager/using/migrating-data-cq.html
// Migrating DITA XML data to Adobe CQ
Reference Post:- http://help-forums.adobe.com/content/adobeforums/en/experience-manager-forum/adobe-experience-manage...
// Migrate website from Teamsite to AEM (XML structures To AEM)
I hope this would help you.
~kautuk
Kautuk Sahni