In first I declare that I am not a vanniyan. I was not took this decision with communal faith. The reasons are listed below.
1. He is not a Keelai Chalukkiyan because Kelai Chalukkiars are from Telungana of Andhra Pradesh. Then why don't he or his forefathers had any capital near Telungana. For example Vijayanagara Kings ruled many parts of Tamil Nadu over a long period but they has Vijaya Nagaram as capital. But Vandhiyaththevan is with Vallam.
2. Vallam was with South Arcot district ( Now it may be named as a new district !! ). The places covered by South Arcot, North Arcot, Salem and Dharmapuri Districts ( Krishnagiri too ) even including half of Karnataka south to Mysore are constantly ruled by Vaanars or their family groups.
I provide few supporting evidences to this claim.
1. Thandampattu Nadukal - Vattezhuththu, 615 - 630 AD, In the period of Mahendravarma Pallavan ( 18 Aam Aatchi Aanndu ), Eesapperum Paanaraiiyar ( Paanar ) ruled a part of South Arcot and North Arcot ( 300 Oorrkal, including Thirukkovilur called Mel Veannadu and Keell Veannadu ). In the same period Vaanakoovariyar ruled West of South Arcot and East of Salem District. This is the same period of Appar Swamigal.
2. Eaduththanur Nadukal - Vattezhuththu, 7th Century AD, - 34 Aam Aatchi Aanndu - Same Rulers.
4. Chinnaiiyan Pettai Nadukal -Thamizhi, Kamba Varman, 3 Aam Aatchi Aanndu ( May be son of Nandhi Varman and brother of Nirupathunga Varman ), Vayiramegha Vaanakoovariyan.
5. Thagaduur Nadukal - 9th Century AD, Arimithaya Mavali Vaanarayar ruled North of Salem Dist to south of Mysore Dist ( Gangapadi ), Dharmapuri, North Arcot and South Arcot.
I didn't find any body other than Vaanar ruled in the above mentioned region.
This made me to conclude Vallavavarayan Vandhiyaththevan as a Tamilian, Vaanan and within this region Vanniyars are the only Kshatriayas I found and by these information I conclude him as a Vanniyan also.
I am interested in truth only. If any body have any evidence that someone else also ruled this region in some period or if somebody can prove the truth is different I am ready to accept it.