TBC Classic
I see frostbite and frostnova both are given the same variable of "PC_ROOT" but the way they displayed are completely different.

  [122] = PC_ROOT,                         -- Frost Nova
    [865] = PC_ROOT,                         -- Rank 2
    [6131] = PC_ROOT,                        -- Rank 3
    [10230] = PC_ROOT,                       -- Rank 4
  [11071] = PC_ROOT,                       -- Frostbite
    [12496] = PC_ROOT,                       -- Rank 2
    [12497] = PC_ROOT,                       -- Rank 3

Where is the scale and location set? What would be the simplest way to make Frostbite aura appear on the top in large scale exactly like Frostnova? Same with pet nova(Freeze) as well actually.

Actually, the classification is not used :) I think they are not shown similarly as one of them is a debuff that's also shown in Blizzard nameplates and the other is not (I would need to verify that). In that case, with default settings, only the first one will be shown as CC, the other one will be shown as regular debuff. You can enable all CCs in Auras - Debuffs - Enemy Units - All (instead of Blizzard).