In order to predict NO formation, we investigate NO regimes for laminar and turbulent flames and suggest a revised NOMANI model. The NO formation is mainly due to two mechanisms: a prompt reaction generated on the flame front with a small time scale and a thermal reaction on the burnt region with a long time scale. Since many previous practical models were based on fast chemistry, there is a limitation in predicting of NO formation in the thermal region. NOMANI model by Pecquery et al. (2014) is based on flamelet-progress variable approach and proposes a new tabulation to the thermal mechanism of NO formation. In the present study, we analyze the various weight parameters using DNS in laminar flames for locally improved NO prediction. The species involved in the NO mechanisms are considered to develop the weight parameters for post flame region and non-premixed flames. LES studies are performed to validate the proposed approach in the turbulent flames.