If you purchase multiple cameras at the time of purchase of new Tata Play Secure subscription, it will be considered as multiple cameras under single Tata Play Secure subscription upto the maximum of 6 cameras and subscription charges will vary as per the camera count

If you purchase multiple cameras over different point of time it will be treated as different Tata Play Secure subscription every time you make a purchase and the subscription charges will vary accordingly depending on the cameras purchased with every new Secure subscription

No, the free trial period will not be extended as per latest purchase date. Free trial for all the cameras under the subscription will be applicable provided there are days left in the complimentary offer tenure as per the initial purchase date of the existing subscription