I found the solution to it
Added the new property under create tag
Step1:-
/apps/cq/tagging/gui/content/tags/createtag/jcr:content/body/items/form/items/wizard/items/createStep/items/fixedColumns/items/fixedC olumn1/items
<newtextproperty
granite:class="block"
granite:id="tagpimid"
jcr:primaryType="nt:unstructured"
sling:resourceType="granite/ui/components/coral/foundation/form/textfield"
fieldLabel="proerty"
name="newtagproperty"
required="{Boolean}true"/>
Step2:-
under /apps/cq/tagging/gui/content/tags/createtag/jcr:content/body/items/form
Change the action to new custom servlet
sling:resourceType="granite/ui/components/coral/foundation/form"
action="/bin/tagcommandcreateext"
Step3:-
I found that ootb component on dialog creation sends data servlet /bin/tagcommand that is com.day.cq.tagging.servlets.TagCommandServlet
so decode and copy this code to your servlet and remove all the unwanted code expect for createtag code
Step4:- under your new servlet which has servlet path with "/bin/tagcommandcreateext"
private HtmlResponse createTag(TagManager tagManager, SlingHttpServletRequest request){
ResourceResolver resourceResolver = null;
Session session = null;
Map<String, Object> subService = new HashMap<>();
subService.put(ResourceResolverFactory.SUBSERVICE, SUB_SERVICE);
resourceResolver = resourceResolverFactory.getServiceResourceResolver(subService);
session = resourceResolver.adaptTo(Session.class);
try {
Tag tag = tagManager.createTag(tagID, request.getParameter("jcr:title"),
request.getParameter("jcr:description"));
Node tagNode = session.getNode(tag.getPath());
tagNode.setProperty("newtagproperty",
request.getParameter("newtagproperty"));
session.save();
return this.createResponse(200, type + " created", tag.getTagID(), tag.getPath());
}...