<h4>Default Value Disabled</h4>

RadioGroupValue1: @RadioGroupValue1

<TelerikRadioGroup Data="@Options"
                   @bind-Value="@RadioGroupValue1"
                   ValueField="@nameof(RadioModel.Id)"
                   TextField="@nameof(RadioModel.Text)">
    <ItemTemplate>
        @{
            var dataItem = (RadioModel)context;
            var isChecked = dataItem.Id == RadioGroupValue1;
        }
        @if (!dataItem.Enabled)
        {
            <span class="disabled-radio-option">
                <span class="k-radio-wrap">
                    <input type="radio" value="@dataItem.Id" aria-checked="@isChecked" aria-disabled="true" aria-invalid="true"
                           class="@( $"fake k-radio k-radio-md {(isChecked ? "k-checked" : "")}" )" style="user-select: none;" />
                </span>
                <span>@dataItem.Text</span>
            </span>
        }
        else
        {
            <span>@dataItem.Text</span>
        }
    </ItemTemplate>
</TelerikRadioGroup>

<h4>No Default Value</h4>

RadioGroupValue2: @RadioGroupValue2

<TelerikRadioGroup Data="@Options"
                   @bind-Value="@RadioGroupValue2"
                   ValueField="@nameof(RadioModel.Id)"
                   TextField="@nameof(RadioModel.Text)">
    <ItemTemplate>
        @{
            var dataItem = (RadioModel)context;
            var isChecked = dataItem.Id == RadioGroupValue2;
        }
        @if (!dataItem.Enabled)
        {
            <span class="disabled-radio-option">
                <span class="k-radio-wrap">
                    <input type="radio" value="@dataItem.Id" aria-checked="@isChecked" aria-disabled="true" aria-invalid="true"
                           class="@( $"fake k-radio k-radio-md {(isChecked ? "k-checked" : "")}" )" style="user-select: none;" />
                </span>
                <span>@dataItem.Text</span>
            </span>
        }
        else
        {
            <span>@dataItem.Text</span>
        }
    </ItemTemplate>
</TelerikRadioGroup>

<style>
    .k-radio-list-item:has(.disabled-radio-option) {
        pointer-events: none;
        cursor: default;
        opacity: 0.6;
        gap: 0;
    }

    .disabled-radio-option {
        display: flex;
        align-items: center;
        align-content: center;
        gap: var(--kendo-spacing-1);
    }

    .k-radio-list-item:has(.disabled-radio-option) input:not(.fake) {
        display: none;
    }
</style>

@code{
    private int RadioGroupValue1 { get; set; } = 2;
    private int RadioGroupValue2 { get; set; }

    private List<RadioModel> Options { get; set; } = new List<RadioModel>
    {
        new RadioModel { Id = 1, Text = "Option 1" },
        new RadioModel { Id = 2, Text = "Option 2", Enabled = false },
        new RadioModel { Id = 3, Text = "Option 3" },
        new RadioModel { Id = 4, Text = "Option 4", Enabled = false },
        new RadioModel { Id = 5, Text = "Option 5" },
    };

    public class RadioModel
    {
        public int Id { get; set; }
        public string Text { get; set; } = string.Empty;
        public bool Enabled { get; set; } = true;
    }
}