The 29-year-old Manipuri is the lone Indian woman boxer in fray at the mega-event after making the cut in the only qualifying tournament - the World Championships in May earlier this year.
The mother-of-two, who is also a multiple-time Asian champion, will face Poland's Karolina Michalczuk - a former bantamweight (54kg) world champion - in her pre-quarterfinal bout tomorrow at 18:30hrs (IST).
The Indian, who was made the face of International Boxing Association's campaign to get women's boxing included in the Olympics, needs to win just two bouts to be assured of a medal, and first up for her is Michalczuk.
Michalczuk, a 32-year-old, won a bronze medal at the World Championships this year.
"The critics and some of my well wishers still want me to prove myself after 12 years in this sport and after winning five World Championships," Mary Kom stated. "I have won my World Championships in 46 and 48kg. These weight categories are not in Asian or Olympic Games. Boxing was introduced in Asian Games only in 2010 and there I got a bronze in 51kg."
"Before that, for over a decade I was fighting in the lower weight categories.
Here also, I am in 51kg, I have no complaints. My critics may not know but I know what I have to do," Mary said.
The boxer has been forced to train without her American coach Charles Atkinson, who has been denied access to the Athletes Village as he does not not have the International Boxing Association's 3-Star certificate for coaches.
'Magnificent Mary', as she is called by the AIBA, will be taking the ring tomorrow with national coach Anoop Kumar by her side and her mother watching her from the stands for the first time in her career.
"I am told if I win two bouts I will be winning a medal. I am not taking things lightly. I am focused because like me, my opponents must also have plans and strategies, let us not forget that," she said.
If Mary Kom wins her opening bout, she will be up against Tunisia's Maroua Rahali, who has got a first-round bye.