For this a list of few simple words of o (ओ) and Au (औ) Matra atra (मात्रा) is given here. After that you are advised to watch the video.
Search online Hindi writing editor in google . You will find two or three efficient editor to write Hindi with keyboard. This will help to ask question in the comment box.
Here is the list of word. You should write these words with the help of someone who can dictate you.
|ओ की मात्रा वाले शब्द||औ की मात्रा वाले शब्द|
| ओक |