Quantum spin liquid (QSL) is an ordered spin state which has been destroyed by quantum fluctuations at low temperatures. Low energy excitations of spin liquids are charge neutral spin-1/2 fermions called spinons. These exotic quantum states of matter are helpful in the field of quantum computing, data storage and in understanding high Tc superconductivity. FeSi behaves like rare earth Kondo insulator. Resistivity of FeSi is metallic at room temperature and shows activated behavior at low temperatures. Cobalt substituted FeSi shows Metal to Insulator Transition (MIT) at 2%. Below MIT concentration and low temperatures, unbalanced count of electrons coupled with under compensation of moments yield exotic properties at low temperatures such as spin liquids & non-fermi liquid. MuSR coupled with thermodynamic measurements is expected to throw light on this scenario.