@Johnbhoy: Sorry to hear that you're having issues with your Tab A6. If you connect the tablet to your official charger and press the Volume Down and Power buttons together for around 10 seconds, are you able to power up the device in this manner? If possible, can you try the same step with another compatible charger, just to make sure it isn't an issue with your current charger.
If the tablet remains unresponsive then recommend visiting a Samsung Support Centre where an engineer can inspect the device for you. To find your nearest one please check the link below, select 'Mobile Device > Phones, Tablets and Wearables' and enter your post code.