Role of magnetic fields (B-fields) and turbulence in star formation is still under debate but considering the magnetised nature of molecular clouds, we expect B-fields to have a significant impact on this process. Observations of molecular clouds in different environments using different astronomical techniques helps in understanding the various important aspects of star formation. I mostly worked towards mapping B-fields in nearby low-mass star forming regions in different environments viz. molecular clouds in isolation and HII regions at their different evolutionary stages using multi band polarization observations. This was done using optical, near-IR, and sub-mm polarization observations to map B-fields from pc to sub-pc scales. In this talk, I will briefly present my work on B-fields in various Galactic regions i.e. cores, filaments, and HII regions. We know that grain alignment is the key to understand interstellar dust polarization. Therefore, I will mostly emphasise on my recently accomplished work on investigation of grain alignment efficiency in PDRs using dust polarization measurements.