Hi welcome - You have to plan a low calorie 1200-1600kcal/day diet plan with 2 hours of exercises outdoor as well some idoor yoga/poses types.avaoid dry fruits, banana, potatoes,fast,junk, too much oil/spices rice, fried foods, or soft drinks, more dynamic less sitting as possible.

11 KGS wieght loss u require u have backache due to heavy weight. Gym can worsen your backache. I can help with 4-5 KGS wieght loss in month

First and foremost you must understand losing your weight is a very gradual process. You should have strong determination and patience if you want to lose weight. And it cannot happen suddenly. Losing too mich suddenly is also not good for health. You have to follow a strict diet and exercise schedule. Regarding diet - have small multiple meals instead of 3 big meals, eat food rich in proteins and fibres like egg white boiled chicken vegetables fruits pulses, avoid carbohydrate rich foods like rice curds oily foods sweets ghee and other junk food. Regarding exercises - start slowly with brisk walking, then change over to jogging, running and other abdominal exercises. Never over strain yourself. And always keep yourself well hydrated and enjoy whatever you do...consult dietitian they will do the needful.

No u cannot join the gym Follow weight loss diet plans Do not skip the meal Include high fiber in your diet Include high protein Drink atleast 12 glasses of water and other fluids like coconut water, butter milk, green tea etc