if else condition in blade file (laravel 5.3)

You don't have to use braces in blade conditions, so your code would be like this:

@if($user->status =='waiting')
    <td>
        <a href="#" class="viewPopLink btn btn-default1" role="button" data-id="{{ $user->travel_id }}" data-toggle="modal" data-target="#myModal">
            Approve/Reject
        <a>
    </td>
@else
    <td>
        {{ $user->status }}
    </td>
@endif

No curly braces required you can directly write

@if($user->status =='waiting')         
      <td><a href="#" class="viewPopLink btn btn-default1" role="button" data-id="{{ $user->travel_id }}" data-toggle="modal" data-target="#myModal">Approve/Reject<a></td>         
@else
      <td>{{ $user->status }}</td>        
@endif

I think you are putting one too many curly brackets. Try this

 @if($user->status=='waiting')
            <td><a href="#" class="viewPopLink btn btn-default1" role="button" data-id="{!! $user->travel_id !!}" data-toggle="modal" data-target="#myModal">Approve/Reject</a> </td>
            @else
            <td>{!! $user->status !!}</td>
        @endif