[AuthorizeRoles(GroupRole.Admin, GroupRole.Netmanager)]
    [Area("Admin")]
    public class CouncilController : BaseController
    {
       public CouncilController(...)
       {
       ...
       }
 
        public async Task<IActionResult> Index()
        {
            await _councilRepository.UpdateCouncilAsync();
            CouncilCandidatesModel model = new CouncilCandidatesModel();
            model.Candidates = _councilRepository.GetCandidates();
            model.CouncilMembers = _councilRepository.GetMembers();
 
            return View(model);
        }
 
        public async Task<IActionResult> GetCandidates(IDataTablesRequest request)
        {
            if (request.Draw > 1)
            {
                Cache.Set(await UserManager.GetUserIdByClaimsAsync(User), "GetCandidates", Request.Form.ToDictionary(p => p.Key, p => p.Value.ToString()));
            }
 
            return View(_councilRepository.GetCandidates());
        }
 
        public async Task<IActionResult> GetMembers(IDataTablesRequest request)
        {
            if (request.Draw > 1)
            {
                Cache.Set(await UserManager.GetUserIdByClaimsAsync(User), "GetMembers", Request.Form.ToDictionary(p => p.Key, p => p.Value.ToString()));
            }
            return View(_councilRepository.GetMembers());
        }
    }
  }

    [AuthorizeRoles(GroupRole.Admin, GroupRole.Netmanager)]
    [Area("Admin")]
    [Route("Admin/[controller]")] // добавленная строка

[HttpPost]

@Url.Action("GetCandidates", "Council")