Risk Fourier Spectra for probabilities of exceedance of.05 and .10 have been calculated for a site in Assam Seismic gap for 100 years return period, using a method which does not make any assumption regarding earthquake recurrence in time and space. Data on past earthquakes and tectonic features have been used to model the seismicity of the seismic gap and the region around it by four different models. Fourier amplitude spectra have been presented for all the four models and specific single earthquake spectra are also depicted for comparison. It is found that a single earthquake assumed to occur at a near distance from the site of interest, gives highly conservative level of risk, whereas the models suggested in this paper provide a more realistic level of risk, because these models take into account the random distribution of earthquakes over a vast area around the site at which risk is estimated.