In my honest opinion 4-6 times is just superfluous and you're almost wasting your time. You're better off doing other things at that point unless it takes that many times for you to understand the text.
Re-reading your text(s) is definitely helpful, but there's only so much you can get out of doing this task and you should have these goals in mind. Specifically, you'll want to be focussing on more minor details or nuanced points that you didn't notice in the first reading. For example, you could begin looking at the way the text is structured. Does it have a bookending feel to it, where it starts and finishes with the same character?
If you don't know how to spend your time on text response preparation, here are some tips:
1. Practice planning. I'd argue this is almost BETTER than doing practice essays because it's just so much more efficient. Try to grab a list of tons of possible prompts for your text. If you don't know where to look, check the VCAA website for past exams or even ask your teacher. Do a plan of all the prompts you can--especially those you feel uncomfortable with. You can then use these to figure out the themes or characters of a text that you're struggling with. Try to get a topic sentence for each of your three to four body paragraphs and select evidence that you'd use from the text.
2. Use a quote bank. They're awesome. Unfortunately, rote learning quotes is a must for text response. You may as well begin this as early as possible so that you can progressively learn them over time. Longevity is key here.
3. Make your own prompts. This method can be effective if you don't have many prompts to begin with and give you more room to work with. It's also a good way to refresh your knowledge of different aspects of a text. Try making prompts of all different natures.
Some different types include:
- a single character or the way characters relate
- a specific theme or multiple themes and how they're explored
- the views and values of the author
- "do you agree?" questions (closed)
4. Look online for resources about your text. If your text is more popular, you might be able to find an in-depth analysis or critical essay. These help broaden your understanding of what's going on. Similarly, look up the history of the author or director and try to understand what was going through their mind in creating the text.