Dear Sayeed
thank you for your message. Building a platform encompasses two aspects. The first one is related to actions of “social marketing”, and I can suggest you see, in Community Tool Box, Chapter 45. “Social Marketing of Successful Components of the Initiative” on the page /en/table-of-contents/sustain/social-marketing and Toolkit 13 “Implementing Social Marketing” /en/implement-social-marketing-effort (in the last one there are a lot of examples). The second aspect refers to the kind of technical support, so the online platform which may be used successfully. In this regard, I may suggest you look online for the best offers, and then choose a platform free (for not having costs for implementation) and easy to be reached, which allows sharing data, organize meetings and so there. You may try yourself the connection, in order to have an idea about possibilities and difficulties. It isn’t easy to suggest some names because it depends to place, connections, required length for attending meetings, and others…
Hoping to have been useful,
many greetings and many wishes for your work!