Scoring around 8to 20 in mock test is there any way to improve my score before November 20th

best option is to find the area in which u r comfortable and try to tak most out of it.
Don't try to learn new things just focus on what you know.

And don't get demotivated , be positive.

just start attempting less questions
particulary if u feel some question too easy or too obvious

Analyze where you are getting wrong and find strong areas to score more on that particular area.