One of the three main surveys of Roman Telescope, to be launched in 2025, is a microlensing exoplanet survey. This survey is going to detect more than 1400 cold low mass exoplanets in Jupiter-like orbits just beyond the snowline - a demographic of exoplanets that is still scarcely explored. But Roman Galactic Exoplanet Survey will revolutionize our understanding of such planets and their effects on eta⊕. The survey will also measure the mass of more than 700 such exoplanets and their hosts. This result, along with previous Kepler data will help us to constrain the eta⊕ and predict for future exoplanet studies like, LUVOIR, HABEX. With this method we have recently detected a lens host about 100 times fainter than the source using Keck AO as part of Roman exoplanet precursor study. We have developed MCMC and Jackknife statistical methods to mediate the effect of changing AO PSFs to detect such faint targets conclusively in H and K infra red passbands. This is one of the faintest lens host detected so far. The ground based study already shows that we can detect faint lens hosting a Jupiter like planet at 7 kpc, very promising result for Roman galactic exoplanet survey.