I done my 12 class in arts stream with economics & math can I get admission in B.Com honours? My 12 percentage is 82.

Yes, you can do B.Com after completing your +2 with any stream, as per your 12th marks is concerned it doesn't matter. Because you need to give CUCET exam and the admission will be based on your CUET score.

Yes, you can pursue B.Com honors with your arts because in undergraduate programme there is no need of commerce and all and your percentage is also good so it will create a problem Regards.