Cannot deserialize the current JSON array (e.g. [1,2,3]) into type

It looks like the string contains an array with a single MyStok object in it. If you remove square brackets from both ends of the input, you should be able to deserialize the data as a single object:

MyStok myobj = JSON.Deserialize<MyStok>(sc.Substring(1, sc.Length-2));

You could also deserialize the array into a list of MyStok objects, and take the object at index zero.

var myobjList = JSON.Deserialize<List<MyStok>>(sc);
var myObj = myobjList[0];

For array type Please try this one.

 List<MyStok> myDeserializedObjList = (List<MyStok>)Newtonsoft.Json.JsonConvert.DeserializeObject(sc), typeof(List<MyStok>));

Please See here for details to deserialise Json