Hi ramitaherwahd...,
Refer below sample.
Model
public class CalEvents
{
    [Key]
    public int EventId { get; set; }
    public string Subject { get; set; }
    public string Description { get; set; }
    public DateTime theStart { get; set; }
    public DateTime theEnd { get; set; }
    public string ThemeColor { get; set; }
    public Boolean IsFullDay { get; set; }
}
Controller
public class HomeController : Controller
{
    private DBCtx Context { get; }
    public HomeController(DBCtx _context)
    {
        this.Context = _context;
    }
    public IActionResult Index()
    {
        return View();
    }
    [HttpGet]
    public JsonResult GetEvents()
    {
        var events = this.Context.CalEvents.ToList();
        return new JsonResult(new { Data = events });
    }
}
View
_Layout
<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>@ViewBag.Title</title>
</head>
<body>
    <div>
        @RenderBody()
    </div>
</body>
</html>
Index
@addTagHelper*, Microsoft.AspNetCore.Mvc.TagHelpers
@{
    ViewBag.Title = "Home Page";
    Layout = "~/Views/Shared/_Layout.cshtml";
}
<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
</head>
<body class="container">
    <div id="calender"></div>
    <div id="myModal" class="modal fade" role="dialog">
        <div class="modal-dialog">
            <div class="modal-content">
                <div class="modal-header">
                    <button type="button" class="close" data-dismiss="modal">×</button>
                    <h4 class="modal-title"><span id="eventTitle"></span></h4>
                </div>
                <div class="modal-body">
                    <p id="pDetails"></p>
                </div>
                <div class="modal-footer">
                    <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
                </div>
            </div>
        </div>
    </div>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css" />
    <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
    <script type="text/javascript" src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js"></script>
    <link href="//cdnjs.cloudflare.com/ajax/libs/fullcalendar/3.4.0/fullcalendar.min.css" rel="stylesheet" />
    <link href="//cdnjs.cloudflare.com/ajax/libs/fullcalendar/3.4.0/fullcalendar.print.css" rel="stylesheet" media="print" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script>
    <script src="//cdnjs.cloudflare.com/ajax/libs/fullcalendar/3.4.0/fullcalendar.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            $.ajax({
                type: "GET",
                url: "/Home/GetEvents",
                success: function (data) {
                    var events = [];
                    $.each(data.Data, function (i, v) {
                        events.push({
                            title: v.Subject,
                            description: v.Description,
                            start: moment(v.theStart),
                            end: v.theEnd != null ? moment(v.theEnd) : null,
                            color: v.ThemeColor,
                            allDay: v.IsFullDay
                        });
                    })
                    GenerateCalender(events);
                },
                error: function (error) {
                    alert(error.responseText);
                }
            })
            function GenerateCalender(events) {
                $('[id*=calender]').fullCalendar('destroy');
                $('[id*=calender]').fullCalendar({
                    contentHeight: "auto",
                    defaultDate: new Date(),
                    timeFormat: 'h(:mm)a',
                    header: {
                        left: 'prev,next today',
                        center: 'title',
                        right: 'month,basicWeek,basicDay,agenda'
                    },
                    eventLimit: true,
                    eventColor: '#378006',
                    events: events,
                    eventClick: function (calEvent, jsEvent, view) {
                        $('[id*=myModal] [id*=eventTitle]').text(calEvent.title);
                        var $description = $('<div/>');
                        $description.append($('<p/>').html('<b>Start:</b>' + calEvent.start.format("DD-MMM-YYYY HH:mm a")));
                        if (calEvent.end != null) {
                            $description.append($('<p/>').html('<b>End:</b>' + calEvent.end.format("DD-MMM-YYYY HH:mm a")));
                        }
                        $description.append($('<p/>').html('<b>Description:</b>' + calEvent.description));
                        $('[id*=myModal] [id*=pDetails]').empty().html($description);
                        $('[id*=myModal]').modal();
                    }
                })
            }
        })
    </script>
</body>
</html>
Screenshot
 
