To add watermark, go to Camera App > Go to Camera Menu > Go to Watermark and click your picture.
If you want to add watermark on the already captured pictures, Go to Gallery > Select the picture where you want to add watermark > Click on Edit > Select Watermark option.
Yes, Honor Holly 3 is Honor India's first made-in-India mobile phone.
Yes, the hardware of Honor Holly 3 does support upgrade to Android Nougat. However, the company has not yet published any OTA Software Update for the same.