Hi @saurabh_kumar_02, you should use separate entry for each extension,
like below@Component(service = Servlet.class, metatype = true, property
= { "sling.servlet.resourceTypes=" + "NameConstants.NT_PAGE",
"sling.servlet.selectors=" + "image", "sling.servlet.extensions=" +
"jpg", "sling.servlet.extensions=" + "jpeg", "sling.servlet.extensions="
+ "png", "sling.servlet.extensions=" + "gif" })