Either you can create URL in controller and pass it to JSP as below
PortletURL liferayURL = PortletURLFactoryUtil.create(renderRequest,<<portlet-name>>, <<Plid>>,PortletRequest.RENDER_PHASE);
renderRequest.setAttribute("anotherPortletUrl", liferayURL);
JSP
click here
OR
You can create Liferay Portlet Render URL in JSP as below
<%@page import="com.liferay.portal.kernel.portlet.LiferayWindowState"%>
<%@ taglib uri="http://liferay.com/tld/portlet" prefix="liferay-portlet" %>
<liferay-portlet:renderURL plid="10180" portletName="portlet-name" var="openForm" windowState="<%=LiferayWindowState.POP_UP.toString()%>"></liferay-portlet:renderURL>
With above two methods you can create a url on click of which portlet on other page will be opened.
If you portlet is instanciable add instance with portletname
window.location.href= "/group/game/portal"
– Pankaj Kathiriya