[Jim McDougall]

Thank you Nihl.
As you note, these markings are intended to imitate European markings seen on trade blades which were often quite present in India, and were more applied in the sense of 'quality' or 'power' so they were not 'artistically' rendered necessarily. It was the implication of what they imbued.
Although on this tulwar, can be seen three dots.

One of the highly copied European markings are the dentated arcs known as sickle marks or Genoan marks. These opposing arcs usually had three dots at the terminus of each arc. While it is tempting to suggest these dots seen on this blade might be from those, it should be noted that many tulwars have these three dots seemingly strategically placed at key places on the blade but alone. There is a suggestion this may have to do talismanically perhaps with the Trimurti, but difficult to elaborate further here. One of the most common markings of the sickle mark kind and similar blades seem to be on Afghan 'paluoars'.

The marks that seem to be imitated here appear to be the so called 'twig' type marks on Italian blades, but difficult to say for certain.

I must admit I am not too familiar with tulwars in Tamil or southern regions, however here I would note that the north Indian (now Afghanistan) version of the tulwar with down turned quillons known as the paluoar is believed to be from Deccani influence. There were notable connections between the Pathans and Southern India so the influences diffusing there would not be surprising.
I would very much appreciate examples of the tulwars from Tamil regions as I have not yet located any, but most references I have are on Hindu and not Mughal arms from the south.
It is known that Tipu Sultan spoke Urdu so the Pathan influences and tulwars most have been there. In British administration in the Raj, the Madras Presidency connected the north and south.