Hi Nidhi,
Loosing weight at home is as effective as working out in gym. But only thing we need to keep in mind is that we need to do more of cardio exercises which can be one of your favorite activity like dancing, swimming, zumba steps, skipping, skiing,etc. We need to do any of these activity for atleast 45 min in a day and loosing 20 kg needs a strong determination with your dedicated healthy diet and regular exercises.