"render inaccessible" is a correct and usable phrase in written English.
Generally, you would use it in a context to describe either a thing or an event that has been made, or has become, unavailable or hard to get to. For example: "Due to the recent flooding, many parts of the city have been rendered inaccessible."
The attic staircase had been rendered inaccessible by a great tumble of over-stuffed bin-bags.
Medications and records for patients in clinical trials were rendered inaccessible.
The cities of North Syria were thus rendered inaccessible to the Hittite armies, except through the Southeastern Taurus passes, and remained so until imperial times.
Twitter is estimated to have about 18,000 active users in mainland China, despite being rendered inaccessible without a virtual private network (VPN) by the country's notorious Great Firewall.
"It's very unsettling," said Clifford Coonan, a correspondent for The Irish Times and The Independent whose e-mail account was rendered inaccessible last week after Yahoo detected that someone had gained access to it remotely.
The Vale of Arryn is rendered inaccessible during the winter due to the surrounding Mountains of the Moon, and the land of Dorne, though graced with pleasant weather, is dominated by deserts.
Religious activities have also been restricted, the ICT said, adding that the path used by the Buddhists around the Potala, the former residence of the Dalai Lama, was rendered inaccessible by the construction of a large stage.
"It's very unsettling," said Clifford Coonan, a correspondent for The Irish Times and Variety magazine whose e-mail account was rendered inaccessible last week after Yahoo detected that someone had gained access to it remotely.
Overall casualty figures for the Philippines were sketchy in the early days after the disaster, especially because so many of the worst-affected areas were remote and had been rendered inaccessible by the storm.
The unanticipated return of almost two million refugees since last year has outstripped both the capacities and the financing of the relief agencies, and the situation may worsen over the winter, when approximately two million people living in areas that will be rendered inaccessible by heavy snows or cold will be particularly vulnerable.
