Hi Neha,

As NCERT have updated some points and still some points needs to be updated . 

It would be fine if you go for latest one. If you can’t, than there is no major issue is doing older versions of NCERT. 

Try to revise NCERT as much as you can because in every revision you will always find some new things that you skipped or don’t consider that topic. 

As every topic is important in NCERT from exam point of view .

for good revision I suggest you the following things- 

• solve or go through the mock or previous years paper 
• then find the mistakes you have done.
• Read that weak topic again and make note if necessary.
• solve all matching questions of NCERT excersice.

As you left with a month. So buckle up and ready for smart and quick revision.

Best of luck 

Thanks:)