IES light spreading, Pixelated lines

[muzaffarkhan]

i have done this render recently, as you can see those ceiling lights are spreading, are they coz of irradiance map? how to i correct it and how much be the values for interp. samples and interp frames??? and the hanging light lines are pixelated, i asked that in other thread also and i got a answer to use GUESS VERT but i m not able to find that GUESS VERT option anywhere. please help that thing makes the render so ugly.