does neet dress code allows jeans for boy candidate

No jeans. It is trousers that are simple and light with no extrinsic buttons, design or embroidery on the trousers. You should team up your trousers with simple and light half sleeved shirt with again no zips, designs, big buttons and embroidery. Your footwear should be either slippers, men's sandals or half shoes. Full shoes are strictly prohibited. No metal whatsoever like rings, bracelets, chains are allowed.