You will be able to find Bamboo chairs with ropes which can be hung from the ceiling, at the ECR Road on the way to Mamallapuram.
You have to bargain with them on the rates. Not just ECR Road, you will also be able to find similar ones close to Swagath Hotel, Royapettah as well as Airport Road which leads now to the x-Kathipara Junction.
Now the Kathipara Junction (as its famoulsy called) has many flyovers nearing completion. So make it on the ground level to get these chairs.
Make sure that these Bamboo chairs are good enuf. I mean test the strength of these chairs. Use your hand and apply weight on the baby chair and see if its able to bear the weight. Make sure the nails are well bent, so as not to harm the child.
Place a quilt or sofa cushion. U must clean the sofa cushion or quilt everytime you want to load the child, becos, there can be ants or other insects clinging on it.
U must be able to get a baby bamboo chair with ropes hanging type for about 250 to 300 rupees.