Due to construction activity going on everywhere in our country the scope of the cement and TMT bars is quite good. You can apply for dealership and enjoy a steady commission on your sales. You can also buy directly from the supplier but margins will be different.
Bangur cement, UltraTech Cement, Bharathi Cement etc are some good brands and you can try to apply to them for dealership.
For TMT bars there are many manufacturers and brands available in the market like TATA Tiscon, PAVAI TMT, AMMAN-TRY, Kiscol TMT, iSteel, ASRM-TRY etc and you can purchase them from the big suppliers also.
You have to create storage and to and fro movement facility for these items and some initial investment will be required for making the yards and warehouses for storage of the same. You will also require some supporting staff for maintenance and security of the place as well as some office workers for maintaining the documents etc related to sales and invoicing and tax issues.
This type of business requires a lot of networking and marketing expertise. Gradually that comes with the experience and remember that hard work is the key to the doors of success.
Knowledge is power.