Unfortunately you will still need to mesh the cage on the inside (which looks very difficult with the particular layout of doors) because the bar spacing is far too large for a hamster and the hamster will either escape or get their head trapped in the bars, which would risk their safety.
To mesh a cage, you need a roll of 1cm square mesh (hardware). It needs to be meshed on the inside (not the outside) because if it's meshed on the outside the hamster can get through the bars and get trapped under the mesh, injuring itself.
To mesh from the inside you need to measure the pieces needed for the roof and sides. Any edges where the mesh is clipped need to be folded under (which is hard on the fingers) to ensure no sharp edges where the mesh has been cut. And you also need to cut out the mesh around the door so the door can still be opened (unless you plan to just not use the door and remove the top bars instead). So you'd need to allow extra room at the cut outs to be able to fold the edges under, then cut out separate pieces for the door larger than the door so you can fold edges over.
You would need wire cutters and plastic cable ties, to attach the mesh to the bars all over so it's securely attached.
It is not a fun job! But it is possible. The alternatives still involve diy (bin cage or ikea flatpack Pax unit) because you would need to make a lid. A bin cage would be easier possibly. You cut out the centre part of the bin lid and mesh that. Link below how to do that. But it's hard to find a bin cage large enough so then you'd need two bins. Cut one end off each of them, slide them together to make one large bin and hot glue them together. The same with the lids. Do you have anyone in the family who is diy minded?
Edit - I've had a look on Ikea India site and there isn't really anything that can be adapted. They don't have the Platsa and the Pax wardrobe frames are probably too big for you - they are huge. And can't see any other suitable cupboard that can be adapted.
You could build an enclosure from scratch possibly. Or there is the Linmon table hack (but that can work out quite expensive and not that different from building one from scratch).
I've also messaged you
