How do split json format and save into table as seperate column

Um.
You do realize that JSON is a string to start with, but that the whole idea of JSON is that it's a "container format" - it holds information which is deserialized into string and non-string classes, including dates, integers, arrays, classes, and so forth.

For example, the JSON string:

[{"RN":"1","QUERY_ID":"1519852833","QTYPE":"W","SENDERNAME":"Name1","SENDEREMAIL":"xyz@gmail.com"},{"RN":"2","QUERY_ID":"1519834488","QTYPE":"W","SENDERNAME":"Name2","SENDEREMAIL":"xyz2@gmail.com"}]

Contains an array of two instances of a class:

public class Example
    {
    public int  RN { get; set; }
    public int QUERY_ID { get; set; }
    public string QTYPE { get; set; }
    public string SENDERNAME { get; set; }
    public string SENDEREMAIL { get; set; }
    }

Deserializing the JSON would give you an array of Example:

Example[] data = JsonConvert.DeserializeObject<Example[]>(myJSON);

If it deserialized to a single string, then there wasn't a whole lot of point in using JSON in the first place!