The Flexible AC Transmission System (FACTS) controllers play a vital role in the power system security enhancement. However, due to high capital investment, it is necessary to place these controllers at optimal locations in the power system. This paper presents comparison of various methods used for optimizing the location of Thyristor Controlled Series Compensators (TCSC) and Thyristor Controlled Phase Angle Regulators (TCPAR) which are FACTS devices. A sensitivity based approach has been used to decide optimal location of TCSC & TCPAR. Three indices obtained in this work are, line loss sensitivity indices, total system loss sensitivity indices, real power flow performance index. All the three techniques have been implemented on 5 bus system and IEEE-14 bus system.