High concentration of radon (²²²Rn), thoron (²²⁰Rn) and their decay products in environment may increase the risk of radiological exposure to the mankind. The ²²²Rn, ²²⁰Rn concentration and their separate attached and unattached progeny concentration in units of EEC have been measured in the dwellings of Muktsar and Mansa districts of Punjab (India), using Pin-hole cup dosimeters and deposition based progeny sensors (DTPS/DRPS). The indoor ²²²Rn and ²²⁰Rn concentration was found to vary from 21 Bqm^-3 to 94 Bqm^-3 and 17 Bqm^-3 to 125 Bqm^-3. The average EEC (attached þ unattached) of ²²²Rn and ²²⁰Rn was 25 Bqm^-3 and 1.8 Bqm^-3. The equilibrium factor for ²²²Rn and ²²⁰Rn in studied area was 0.47 ± 0.13 and 0.05 ± 0.03. The equilibrium factor and unattached fraction of ²²²Rn and ²²⁰Rn has been calculated separately. Dose conversion factors (DCFs) of different models have been calculated from unattached fraction for the estimation of annual effective dose in the studied area. From the experimental data a correlation relationship has been observed between unattached fraction (f^Rn_p) and equilibrium factor (F_Rn). The present work also aims to evaluate an accurate expression among available expression in literature for the estimation of f^Rnp .