Considering you are innovative to have invented something of your own i would say you are in the 1 or 2% of startups forum members, most of us are still in the process of doing so , and have invested a few years already in the process
Your product has potential for the millions of poor households all over the country, but you must have the patience and the strength to wait for your time of opportunity.
The main take away from your cooker invention is of course the lessons you have learnt and the hard work that you have put into the process. While you might be successful in selling the Intellectual Property to make ends meet, what of course is equally valuable is your inventing prowess, which you must keep safe, until it can be used again.
What are the skills you have learnt in the process of inventing your cooker ?
Those skills should land you a decent job in the manufacturing industry, with a bit of luck.
Try contacting ITI , Bangalore they should be able to give you practical advice.
If your product it is still in pilot form, i think you should still work towards perfecting it and then doing some marketing / advertising to get in touch with interested folks.
You need to get in touch with a good marketing agency , who can help you market your solar cooker . There are many marketing people in the Indian Startup ecosystem with a good heart who can help you market your solar cooker for a minimal fee.
I personally recommend my friend @tapabrata.maitra who is a marketing campaign manager & trainer. He is also forming his startup and i am sure he would like the opportunity to work with you and market your solar cooker, assuming it is in some sellable condition.
This is just a suggestion.