I want to find out is there any jquery reference in SharePoint master page/page layouts. Can it be possible to read .master data
2 Answers
You can open the site collection in SharePoint Designer and check source of the current master page as described here: https://support.office.com/en-us/article/customize-a-master-page-to-brand-your-site-0a57b837-4c97-4af9-a088-fedf3dfd1dd5#__toc292276844
Another trick without SharePoint designer,
You can use the console at developer tools,
- Open the page that use the layout/ masterpage
- hit f12 to open developr tools
- write a simple jquery code like document.ready(), if it's defined it means you are using jquery