Hello Rocky,

Remember that the JEE advance paper has a different pattern where more than one answers can be chosen if true. In that case the guess work would never help. However, a constant practice during this extra month van definitely help you gain a significant amount of confidence in choosing the right answer. 

If you're revising for IIT JEE Advance in the last month you've to keep few things in mind.

• Dedicate your maximum time for the revision of the important topics and keep away from all the distractions.
• Try solving previous year papers and sample papers as much as possible.
• Do not start with a new topic in this time rather focus on sample paper doubts and clear all your weak points.
• Attempt atleast 1 mock tests everday. This will help you gain some confidence in writing your answers.
• Make sure you're not ignoring your health as that will have an adverse effect on your preparation.
• Do not overthink about one thing and start revising whatever you already know and make a note of all your weak points to clear later.
• Take help of your friends and teachers if you get some doubts in any important topics but don't waste too much time on one topic.

I hope you find this information helpful. All the best.