what is Text confirmation ? Is it something which is sent to person's mobile phone who is giving the test ?Thankyou. I'm still not too sure about 6 month stay, although someone recently in this thread shared IRCC agent's response which states that if they specifically do not give you a return date stamp, then person can stay upto 6 months. I guess we should believe agent's word.
Regarding Covid test lot of people are getting done from private labs as well like Lal path lab have really good reputation. As long as a person has nicely printed report which includes all essential details, there shouldn't be a problem. Not everyone is able to get hold of ICMR approved lab but if you can, go for it. Yes text confirmation is asked from each and every passenger.