You probably should have post this on the general HSC forum instead of maths forum(you are likely to get a lot more replies)-however, simply put, it is only 15%, and you still have 85% of internal marks up for grabs-you are still able to get a band 6 if you think you can and if you undertake constructive actions to make it possible.
Just consider this, your ATAR is dependent on your performance in your external HSC exam as well as your cohort's performance as well as your rank, so although marks are very important, ranks are slightly more-and it is not impossible to get band 6, just keep things into perspective, you have many more assessments to go-probably with your trials weighting the most-and you have a lot of chances and time to improve.
"I just need advice on whether if i am still able to get a band 6, as i only got 70% in first maths assessment that was worth 15%...and the highest was about 92%."
You are asking the wrong question, you should be asking "I need advice on HOW I can get a band 6" and not 'WHETHER I can get a band 6". You should not be letting how you perform in 15% of your marks influence how you are going to perform in the remaining 85% of your marks. So the following are my top tips for maximising your maths potential and maximising your chance of getting a band 6
1)Ask your teacher of why you got each question wrong-what is the correct answer and think to yourself-was it because of poor time management in the exam or in exam preparation time? Was it because of excessive nervousness or was it because you rote learned concepts without understanding and practicing problems? You must understand the CAUSE of your bad marks before you can rectify it and minimise a repetition of your mark in future exams.
2)you have got 6 weeks of holidays ahead of you, which means you should make a study plan and include maths as a large part of it to make sure you COMPLETELY understand all the concepts you have been taught, and you practice it thoroughly as well as even considering to study ahead so when you learn the concepts-it is like revision and you are more likely to get higher marks with more time to practice during the term.
3)Try to both understand, synthesise concepts and above all-when you understand and remember them, do practice questions-from textbooks, from past HSC exams, preferably within a set time limit-it is only be practicing and evaluating your answers-either by checking with sample answers or getting your teachers to mark it for you-and repeating this process constantly through the entire year-will you be able to achieve your goal
If you do bad in one assessment task in one subject and you are already doubting whether an ATAR is out of your grasp at the start of the year-this is slightly too dramatic, you will be encountering good results and bad results for this year-it is normal, rarely anyone will get perfect result every single time-the important thing is you learn from it, maintain a positive psychological mindset and keep working hard and smart-all my best wishes for the year(and don't give up-ever). I have faith you can reach your goal
One more thing-don't need to compare yourself with other people, stop caring about what other people got-just focus on yourself and improving upon your previous results. Comparing with others is meaningless, but beating yourself is meaningful
Just try your best and your result will gradually be the best if can be
