How many settlers died in the first 6 months in Jamestown?

To date, historians estimate that about 70 settlers died in the first six months in Jamestown. About 110 settlers comprised the original contingent of colonists at Jamestown in May 1607. Historians estimate that, of the 110 men and boys, only about 40 were still alive to greet the first supply ships in January 1608.
Although the original settlers had great hopes for the settlement in the New World, many did not bargain for the harsh conditions upon landing. First, the settlers chose to situate themselves on a peninsula off the James River. Although this location was easy to defend and afforded easy unloading of their ships (the waters were deep enough), it provided little access to good hunting.
The settlers eventually hunted all of the wild game to be found on the strip of land. Additionally, the brackish waters of the James River provided poor drinking water. That, added with the presence of disease-carrying mosquitoes, led to the demise of about 70 of the first settlers. The settlers traded for a time with the local Native American tribes (led by Powhatan), but relations soon soured.
All in all, disease, a lack of food, and a lack of good water led to the demise of many of the first Jamestown settlers. To a lesser extent, attacks by Powhatan's tribes also contributed to the death rate. This is why when the first supply ships reached Jamestown in January 1608, only about 40 of the original settlers were still alive to greet them.
https://www.britannica.com/place/Jamestown-Colony