Thyristor controlled series compensator (TCSC) device is a series compensator to govern the power flow by compensating the reactance of the transmission line. Both capacitive and inductive reactance compensations are possible by proper selection of capacitor and inductor values of the TCSC device which can be realized through reactance equation. This paper presents a conceptual study to adopt an apt value for the capacitor and inductor of a TCSC device. Degree of Series compensation (K) brings an idea of selecting the TCSC capacitor. The Reactance characteristic curve is analyzed with resonant point for different values of 'ω' which defines the square root of ratio between capacitive and inductive reactance. The study is helpful in selecting an appropriate value for TCSC inductor which has influence on multi resonance point in TCSC device. Additionally, power flows in the transmission line are discussed with tabulation to realize the operating span of the TCSC for various values of 'ω'. While designing, TCSC parameters can also be selected as per requirement on end side demands and for safe operating span of a TCSC. ©2011 IEEE.