Original sentence: E..Sarasvatī river along with Dṛṣadvati and Āpayā river  formed a delta called Brahmāvarta.Over and over the Vedas mention a mighty river called the Sarasvatī where Vedic civilization flourished and dispersed when the Sarasvatī river dried up around 1900 BCE,another theory says that Sarasvatī started drying up in the year 2525 B.Sahyādrikhaṇḍa even mentions that,a group of artisan brahmins called as Śaivagāyatrī brahmins used to exist in Goa before the advent of Daivajña tribe in Goa.Scholars argue that this tribe migrated to Goa in 4th to 6th century AD,but period of migration of Sārasvata's is dated back to 700 BC,some theories say 2500 BC,which is quite confusing.and dried up totally in 2075 B
Edited sentence: Its even possible that they intermingled with them as few common gotras are found between the two groups.Over and over the Vedas mention a mighty river called the Sarasvatī where Vedic civilization flourished and dispersed when the Sarasvatī river dried up,his change is estimated by geologists to have occurred between 5000 and 3000 BC, that is, before the Mature Harappan period.Sahyādrikhaṇḍa mentions that,a group of artisan brahmins called as Śaivagāyatrī brahmins used to exist in Goa before the advent of Daivajña tribe in Goa.Sarasvatī river along with Dṛṣadvati and Āpayā river  formed a delta called Brahmāvarta.Scholars argue that this tribe migrated to Goa in 4th to 6th century AD,but period of migration of Sārasvata's is dated back to 700 BC according to some scholars whereas some theories estimate it to be around 2500 BC,which is quite confusing