Electron cyclotron resonance (ECR) produced toroidal magnetized plasmas is investigated in a device named 'STARMA', an acronym for Simple Tight Aspect Ratio Machine Assembly, having major and minor radius of 10.4 cm and 6.8 cm respectively with aspect ratio (A) of ~ 1.5. The plasma is formed using a 6 kW magnetron based microwave source operating at 2.45 GHz, employing ECR techniques at a toroidal magnetic field of ~875G. The unique property of this device ensures a large variation of toroidal magnetic field (from 2 kG to 0.4 kG) across the poloidal cross section of the device and supports favorable magnetic fields of 875 G (for fundamental mode) and 437 G (for 2nd harmonic) for concurrent accommodation of fundamental and 2 nd harmonic resonance ECR breakdown, when microwave power at 2.45 GHz is used to form the plasma. In this scenario, the ECR wave-plasma interaction becomes more complex when the plasma production scheme includes simultaneously both, the fundamental and second harmonics of the ECR wave within the plasma volume. This novel technique of plasma production, involving both the fundamental and second harmonic of ECR waves, becomes relevant to small aspect ratio machines and therefore is studied in details. The contours generated from the measured plasma density suggests formation of slab geometry plasma in poloidal cross section of the machine and confirms elongated plasma in vertical direction. The radial profile at the equatorial plane suggests that plasma is formed with density (𝑛 𝑒)~ (1 − 7) × 10 16 𝑚 −3 and electron temperature (𝑇 𝑒) ~(3 − 30) 𝑒𝑉. The plasma is expected to exhibit complex behavior of mode conversion (O-X-B mode conversion), particularly when O and X-modes are launched from the low field side (LFS) at varied angles (𝜃) with respect to toroidal magnetic field (𝐵 𝜙). The subsequent conversion of X-mode into the Electron Bernstein Wave (EBW) at the upper hybrid resonance (UHR) emphasizes on mode conversion affecting parameters like density scale length (𝐿 𝑛 𝑒) and magnetic field scale length (𝐿 𝐵 𝜙) near the UHR. Therefore experiments, relevant to the mode conversion is also carried out by varying the toroidal launch angle up to 10 o. The Budden parameter (𝜂) for experimental conditions are estimated which serves as a milestone in the investigation to understand the OX -B mode conversion process. The verification of the OX mode conversion has been also done using the full wave simulation as WKB approximation is not applicable here. Experiments further suggest that the launching of the Xmode from the outboard side introduces large fluctuations and may be responsible for destabilizing the entire plasma production process.