All males having R1a mutation share a common male ancestor between 18000-30000 year. Now there are many more mutation within R1a haplogroup so we can trace more recent common ancestor. Z-93 is a branch of R1a, it is called R1a1a1h. There are some sub-branches of R1a1a1h too.
Abhi tak aapne bhu garbh vaigyanikon ke tark ke viprit mein koi tathya nahi pesh kiya hai. Kya aap bataane ka kasht karenge ki kyon vaigyanikon ke pramaan ko aap nahi maan na chahate hain saraswati nadi aur Rigved ke vishay mein?
http://www.gsbkerala.com/aryans.htm
Who were the Aryans and where did they come from?
The word Aryan comes from the Sanskrit arya meaningnoble. Historians believe the original home of the Aryans was in the lands south of the Ural Mountains in what is now Kirghizstan. When life became tough, because food was scarce, drop in temperature and the pressure applied by the yellow-skinned tribes in the north, the Aryans began to move away in different directions. Some went to Greece, some to Iran, and some to Afghanistan. From the eastern front some groups moved to India. The whole process of migration took place between 2000 to 1500 BC. They entered India from the north west and initially settled in the land between the tributaries of the River Indus. There were more than 1200 such settlements of migrants.
Many of them settled along the banks of Saraswati river. They settled to an agrarian life, supplemented by cattle grazing. These settlers along the banks of Saraswati river came to be known as Saraswats.