One compound is Completely Hydro Carbon and aromatic. The another one also but having Two Halogens. Even eluting the mixtures in Preparative TLC by n-pentane, the spots were not separating. I wants to separate the Compounds without Prep.HPLC.
I'm assuming you are using silica gel. If they run together using just pentane, they are very non-polar. Try alumina instead of silica since it may have a different selectivity. If that doesn't work, try TLC with a bonded-phase silica such as cyano or diol. These will run as normal phase, with pentane being a weak solvent and other solvents, such as toluene, ethyl acetate, and so forth, being strong solvents.
Sometimes mixture of two or three solvents may work well. For example instead of using n-pentane, try a mixture of DCM and EtOAc (1:4). Adding a few drops of organic acids may help.