Yes. You can go for this trek.
What is the chance of suffering from AMS while trekking to Roopkund lake?
For any high altitude trek, there is a certain amount of chance of suffering from AMS. Roopkund is also not an exception. But proper acclimatization can help avoiding AMS easily.
What about the safety during the trek?
Trek organizers do not provide any guarantee for safety. Experienced guide and team will be there with each group to take care of any issue. Oxygen cylinder, first aid facility will be available during trek. For any medical emergency on spot decision will be taken by trek leads.
Will I get packaged drinking water while trekking?
You will get normal drinking water at each camping point. If you want mineral water then you can buy whenever available enroute.
Do You have any questions in Mind?