function breakSecurityInheritance(lastItemId) {
    var siteUrl = _spPageContextInfo.webAbsoluteUrl;
    var clientPContext = new SP.ClientContext(siteUrl);
    var collGroup = clientPContext.get_web().get_siteGroups();
    var oList = clientPContext.get_web().get_lists().getByTitle($('[id$=hdnHomePagePreviewList]').val());
    this.oListPItem = oList.getItemById(lastItemId);

    // Authoring group permissions start
    oListPItem.breakRoleInheritance(false, true);

    var allGropIds = $('[id$=hdnAllAuthoringGroupIds]').val().split(';');
    for (var v = 0; v < allGropIds.length; v++) {
        var groupDetails = allGropIds[v].split(',');
       if (groupDetails[1] == "Contribute") {
            var collRoleDefinitionBinding = SP.RoleDefinitionBindingCollection.newObject(clientPContext);
            collRoleDefinitionBinding.add(clientPContext.get_web().get_roleDefinitions().getByType(SP.RoleType.contributor));
        }
        else if (groupDetails[1] == "Full Control") {
            var collRoleDefinitionBinding = SP.RoleDefinitionBindingCollection.newObject(clientPContext);
            collRoleDefinitionBinding.add(clientPContext.get_web().get_roleDefinitions().getByType(SP.RoleType.administrator));
        }
        else if (groupDetails[1] == "Read") {
            var collRoleDefinitionBinding = SP.RoleDefinitionBindingCollection.newObject(clientPContext);
            collRoleDefinitionBinding.add(clientPContext.get_web().get_roleDefinitions().getByType(SP.RoleType.reader));
        }
        var oGroup = collGroup.getById(groupDetails[0]);
        oListPItem.get_roleAssignments().add(oGroup, collRoleDefinitionBinding);
    }
    // Authoring group permissions end

    clientPContext.load(oListPItem);

    clientPContext.executeQueryAsync(Function.createDelegate(this, this.onQueryPermissionsSucceeded), Function.createDelegate(this, this.onQueryPermissionsFailed));
}

SPGroup group = web.SiteGroups[groupName];
 SPRoleAssignment roleAssignment = new SPRoleAssignment(group);
 SPRoleDefinition roleDefinition = web.RoleDefinitions["Approve"];
 roleAssignment.RoleDefinitionBindings.Add(roleDefinition);
 roles.Add(roleAssignment);

else if (groupDetails[1] == "Approve") {
        var collRoleDefinitionBinding = SP.RoleDefinitionBindingCollection.newObject(clientPContext);
        collRoleDefinitionBinding.add(clientPContext.get_web().get_roleDefinitions().getByName('Approve'));
    }