I would like to fund my social startup via blockchain. I realized that most of startups here are getting funded via ICOs, they create coins and they distribute coins to investors. My app is social one like Snapchat or Vine, it doesn't require coins. Can I look for investment via blockchain without ICO and coins?
Your request has a fundamental contradiction that makes it unlikely to work. If your product doesn't require any coin/token, then it's not on the blockchain. The coin /token is necessary to keep on mining, and thereby keep that blockchain alive.
You can look for investments without ICO and coins, but that's traditional investing. Given these constraints, you may seek out the Angels and VCs, or try your luck at some of the crowdfunding sites like Kickstarter.