Woud you please discuss the complications of general anaesthesia given for making a surgery?

There should be none: There are risks to undergoing anesthesia up to and including death. However, general anesthesia, when provided in a careful manner by a trained anesthesiologist should be free of complications. Common adverse reactions are nausea and vomitting postoperatively and a sore throat (from the breathing tube). These are temporary.

Rare: It is not normal to ask someone to put you to sleep while another works on you. The risks are minimal, in fact i tell my patients that they are more likely to have problems driving to the hospital to have the surgery. The real risks are usually nausea and vomiting. Talk to your anesthesiologist before the operation and they can give you medications to relieve your anxiety.