<type name="MagentoSalesModelOrderEmailSender">
        <plugin name="module_name::aroundPrepareTemplate" type="modulenameModelOrderEmailSender" sortOrder="99999"/>
    </type>

<?php

    namespace modulenameModelOrderEmail;

    use MagentoSalesModelOrder;
    use MagentoSalesModelOrderEmailContainerIdentityInterface;
    use MagentoSalesModelOrderEmailContainerTemplate;
    use MagentoSalesModelOrderAddressRenderer;


    abstract class Sender
    {

        protected $senderBuilderFactory;


        protected $templateContainer;


        protected $identityContainer;

        protected $logger;


        protected $addressRenderer;


        public function __construct(
        Template $templateContainer,
        IdentityInterface $identityContainer,
        MagentoSalesModelOrderEmailSenderBuilderFactory $senderBuilderFactory,
        PsrLogLoggerInterface $logger,
        Renderer $addressRenderer
        ) {
            $this->templateContainer = $templateContainer;
            $this->identityContainer = $identityContainer;
            $this->senderBuilderFactory = $senderBuilderFactory;
            $this->logger = $logger;
            $this->addressRenderer = $addressRenderer;
        }


        public function aroundPrepareTemplate($subject,Order $order)
        {
            $this->templateContainer->setTemplateOptions($this->getTemplateOptions());
            $objectManager = MagentoFrameworkAppObjectManager::getInstance();
            $orderItems = $order->getAllItems();

            foreach ($orderItems as $item) {

                $product = $objectManager->get('MagentoCatalogModelProduct')->load($item->getProductId());
                $categoryIds = $product->getCategoryIds();

            }
            foreach($categoryIds as $catid){
                $_objectManager = MagentoFrameworkAppObjectManager::getInstance();
                $category = $_objectManager->create('MagentoCatalogModelCategory')
                ->load($catid);
            }


            if ($order->getCustomerIsGuest()) {
                $templateId = $this->identityContainer->getGuestTemplateId();
                $customerName = $order->getBillingAddress()->getName();
                } else {
                $templateId = $this->identityContainer->getTemplateId();
                $customerName = $order->getCustomerName();
            }

            if($catid == 461){
                $templateId = 11 ;
            }


            $this->identityContainer->setCustomerName($customerName);
            $this->identityContainer->setCustomerEmail($order->getCustomerEmail());
            $this->templateContainer->setTemplateId($templateId);
        }


    }