Based on recent trends in Indian Ecommerce industry, earlier there were lot of small and mid-tier companies wanting to go online and building their own direct e-commerce sites. This was partly due to the exhuberance in the sector.
We still have many traders, and small companies, which sell but they have realized that it is better to sell on Amazon or Flipkart to get scale.
Lot of the providers who are mid-size, are focussed on using - Magento, Shopify, Prestashop, or local platforms like StoreHippo, ZenCommerce, etc. These still require customization and setup, and you can operate in that.
I would say it might be better for you to focus on providing Web Development services using a platform, and look for customers in that. This can also expand the market for you as a person looking for ecommerce using a platform can be global.
ps: Further to win new customers, agencies/design firms are bundling packages like Push Notifications (We run PushEngage), Email marketing etc, and that differentiates and provide a one stop solution.