Hi@akhtar,
You can set notification system for your instances. You can use SNS topic and Lambda function to do that.
import json
import boto3
client = boto3.client('sns')
def lambda_handler(event, context):
    topic_arn = 'arn:aws:sns:us-west-1:074796737877:Notification'
    message = 'Instance stop please look on'
    client.publish(TopicArn=topic_arn,Message=message)
    # TODO implement
    return {
        'statusCode': 200,
        'body': json.dumps('Hello from Lambda!')
    }
Hope this will help.
Thank You