In previous papers various True Random Number Generators (TRNG) and Physically Unclonable Function (PUF) are discussed individually but only a few of them include unified TRNG and PUF. TRNG’s are used in cryptography and simulations for conditions in background noise that impact the system. for a PUF its very unlikely to make another device alike due to various intrinsic properties during manufacturing process. PUF’s have various applications which include low-cost authentication, secure key generation. In this work a new architecture of unified true random number generator (TRNG) and physically unclonable function (PUF) is introduced based on ring oscillators with high Uniqueness, reliability, throughput, entropy. The main working of circuit is dependent on two reference values Nij and Nref . The PUF response is based on various intrinsic variables whereas TRNG’s randomness is based on LSB of the Nij . With the current method, results and analysis indicates increase in uniqueness, reliability and other parameters compared to previous papers. The whole circuit is designed using 45nm CMOS technology.