In 10.6, we don't have a separate option to notify technicians under the Business rules option. However, we have introduced something called custom action where more actions could be accomplished.
As for notifying a technician/somebody when a Business rule is executed, you can use the below Deluge script under custom action. In the Business rule, click on select custom action - > custom function and save the below script as shown in the attachment.
requestID = requestObj.get("id");
requester_details = requestObj.get("requester");
request_details = requestObj.get("request");
sendmail
[
from: "abc@xxx.com"
to: "cde@yyy.com"
subject: "HELLO TEST"
message: "Hello, Thank you for reaching out to us. We have received your email and created a ticket to track your question. Your ticket number is " + requestID + ". We will respond within 24 hours. Please respond to this email if you have additional questions. Have a great day, Test Tickets"
];
returnObj = Map();
returnObj.insert("result":"success","message":"Mail sent successfully");
return returnObj;