When a person is traveling and brings the item there won't be many restrictions on whether the product is used or not. 50k is the duty-free limit and anything exceeding that will be taxed at 41.25%. You have to be able to prove the value of the item through invoices etc. But of course, you can just walk through the green channel as well if you're able to prove the value is indeed under 50k for all items combined.
I see. Actually Dummy IEC is a rip-off that these CHA use to charge us 3k to 7k. But, in reality, it takes 1 day for an individual to generate his IEC and it costs 500 INR. All you need is a PAN, Bank account (savings acc also works) and a canceled cheque.
Now DGFT offers IEC to individuals too and GSTIN is not needed as well. They also have a very active and helpful Helpline one could call to clear all of the IEC related queries. For individuals, the PAN becomes the IEC Code.