Have gone for AMC (paid ~3500 Rs). Now let me tell you whats happening...
1) First of all their phone does not work..
2) If someone picks by mistake, they will say the area does not fall under their area. You will be give another phone contact.
3) They will give you another phone contact - again they will point you back..
4) FInally if you get to someone and report for visit. No visit in time.. They will promise for next day which will never comes. It may take 10 or even more days.
5) The person will come - he will tell you the membrane (which is heart of this RO system.) which needs to be replaced is not in stock....
6) Again wait for days and days... I am still waiting. Its almost a month.
Please please do not fall under their trap..
DO NOT BUY... Better look for other options..
They are just good at selling but nothing after that... You are by your own....