Wikipedia
Nimbarka is known for propagating the Vaishnava Theology of Dvaitadvaita (dvaita-advaita) or “dualistic non-dualism". It is also known as 'Bhedabheda' (bheda-abheda) philosophy. According to scholars headed by Prof. Roma Bose, he lived in the 13th Century, on the assumption that Śrī Nimbārkāchārya was the author of the work Madhvamukhamardana. According to Nimbārka Sampradāya, however, Śrī Nimbārkāchārya appeared over 5000 years ago, in the year 3096 BCE at the time when the grandson of Arjuna was on the throne. He hailed from the present-day Andhra Pradesh, in South India. Mungi Village, Paithan which is now in East Maharashtra is also considered as his birthplace.
Bhandarkar has placed him as a philosopher after Ramanuja and has maintained his demise date as 1162 AD. Some hold that he is dated around 13th Century. However, S.N.Dasgupta dated Nimbarka to around middle of 14th Century. On the other hand, S A A Rizvi assigns the date of Circa 1130–1200 AD. But Jadunath Sinha has counted him as a 13th-century philosopher, and Tarachand has held him to be a younger contemporary of Ramanuja.
Current scholarship has pointed out that in Bhandarkar's own work it is clearly stated that this was an approximation based on an extremely flimsy calculation, yet most scholars chose to honour his suggested date, even until modern times. Current scholars have demonstrated with a high degree of clarity that Nimbarka and his immediate disciple Shrinivasa flourished well before Ramanuja, and that Shrinivasa was a contemporary, or just after Sankaracarya. This clearly settles the debate, pending an in depth investigation of this already tested hypothesis, that Nimbarka is a contemporary or just before Sankaracarya.