I need to add a video just above the Title "Property Gallery" ie, just after Property Details.

You can either Upload a video file to your gallery click or while accessing the home page , click  the + sign while hovering over a content section. Select add an about property section , given it a menu title if youd like it to appear in the site main navigation, Then give it a regular title or leave it blank (doesent matter), then paste your embed code in the WSYWIG area, and you should be good to go. ( see screenshot)