There's one company having an office here (where I live) who offers annual interest rates as returns if we invest in their company. They are into funding building developers for making properties, investing in land, commission from 3rd party properties they sell, earnings from their own properties all over the world. Is this interest income halal? Note : the interest rate earnings are fixed and principal will be paid by them on Maturity of the investment term

Yes. It is halal, if they are non-Muslims.
However, my advice is to keep away from such companies, as usually you will eventually loose your money