<style>
    .my-radiogroup {
        height: 160px;
        width: 280px;
        display: flex;
        flex-direction: column;
        flex-wrap: wrap;
    }
</style>

Chosen number: @( ChosenNumber == 0 ? "no selection yet (0)" : ChosenNumber.ToString() )
<br />

<TelerikRadioGroup Data="@NumberOptions"
                   @bind-Value="@ChosenNumber"
                   Class="my-radiogroup"
                   ValueField="@nameof(NumberModel.NumberId)"
                   TextField="@nameof(NumberModel.NumberText)">
</TelerikRadioGroup>

@code{
    int ChosenNumber { get; set; }

    public IEnumerable<NumberModel> NumberOptions = Enumerable.Range(0, 10).Select(x => new NumberModel
    {
        NumberId = x,
        NumberText = "Number " + x
    });

    public class NumberModel
    {
        public int NumberId { get; set; }
        public string NumberText { get; set; }
    }
}