Walk is the best exercise for you n dnt compare it with treadmill. Do early morning walk regularly for half an hour. Eat fresh fruits and vegetables. Dont make a gap of 4 hrs in between meal. Control on stress n mood fluctuation otherwise u unbalance ur metabolism which make ur weigjt more plateu.

Hi,Your ideal weight is 66kgs. A calorie deficit diet but balanced in all nutrients can help you loose weight. Rigorous gymming is not necessary, just 150minutes exercise per week gives your muscles enough exercise and rest for the week. (Unless you are trying bodybuilding). Diet depends on a lot of factors and seeking professional help for that is a good idea. As you are a vegetarian, adding paneer, milk & curd to your diet is necessary.