Start Up India is a campaign that was launched under Ministry of Commerce and Industry to facilitate fund for people want to start their own business entity. However there is a department that fully monitor and manage. So, it can be easily said that monitoring authority for the campaign is Ministry of Commerce and Industry.
However there is an involvement of different miniseries also in different ways, like:
1- Ministry of Human Resource Development
2- Department of Science and Technology
These ministries do partnership in an initiative to set up more than 75 startup support hubs in IISER, IIT, NIT amd NIPERs.
If we talk about investment, SoftBank Group Corp. which is the bank of Japan has invested in $2 billion USD into Indian startups.
All the process related to start up loan from registration to loan distribution, Start Up department India manage from itself.
If it talks about investment, start up India allows you to take loan under it. There is no scene has come that a common business entity has invested in it. However as I have mentioned above, Softbank made the investment in the scheme. However, if you are looking for invest you may contact the Ministry of Commerce and Industry or can text them at their online site.