Help for Aimeos

The easiest way is installing the ai-payments extension and using an Omnipay driver. For Paytm there's already one implemented:
https://github.com/sumityadav/omnipay-paytm

You should try if it works out of the box. Sometimes minor fixes are necessary to get drivers running.

You can always recreate these attributes by running the Aimeos setup

You may have forgotten to extend from the existing class like this:

You can copy and extend from the existing factory ( https://github.com/aimeos/ai-controller-jobs/blob/master/controller/jobs/src/Controller/Jobs/Product/Import/Csv/Factory.php ), e.g. to a sub-directory controller/jobs/src/Controller/Jobs/Product/Import/Csv/Clothes/Factory.php in your own Aimeos ext...

The easier way would be to add a translatable hint for the code like realized here:
https://github.com/aimeos/ai-client-htm ... t.php#L124

Not in the database but you can translate the type codes into different languages in the frontend like here:
https://github.com/aimeos/ai-client-htm ... t.php#L122

Can you explain that in more detail please?

Can you explain which parameter you would like to add for what reason?

Use brands as categories and models as sub-categories and add your articles to these categories. If you have parts that exists in different variants (e.g. in different colors), then use selection products to group the articles together.

You should have a look at the ai-payments extension which does that already:
https://github.com/aimeoscom/ai-payment ... y.php#L724