LINQ General query Error

Why are you using linq this way? If you need sql query, build it and pass to the command. Linq is not an alternate way to write sql statements. Any by the way you have select missing from both linq statements (is not necessary, but should be used), plus you declared the Lqry variable inside the block, thus out of scope of the second part of the code. And why have you made two queries for that?

First, few things:
1. var is a compile time constant and its scope remains within if{...} or else{...} (in your case). In general within parenthesis {...}
2. The LINQ statement gets executed only when use the LHS variable in the statement.
4. Syntax of the statement is wrong.
3. Do not mix LINQ and SqlCommand. Use either of them.

So,
First,

if(Status==1)
{
 
var Lqry = from A in DC.CLRN_Tables
           join B in DC.CLRN_Tables2 on R.ID equals B.ID
           where (A.STATUS == "1") && (B.iStatus == 1)
SqlCommand cmd = (SqlCommand)DC.GetCommand(Lqry); // This Lqry is common 
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                da.Fill(dsTR);
}
 
if(Status==2)
{
var Lqry = from A in DC.CLRN_Tables
           join B in DC.CLRN_Tables2 on R.ID equals B.ID
           where (A.STATUS == "1") &(B.iStatus == 2)

SqlCommand cmd = (SqlCommand)DC.GetCommand(Lqry); // This Lqry is common 
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                da.Fill(dsTR);
}

By doing this, the scope of Lqry remains within if

Second,
The LINQ statement gets executed when you use it. What I mean by this is, when you write this

var Lqry = from A in DC.CLRN_Tables
           join B in DC.CLRN_Tables2 on R.ID equals B.ID
           where (A.STATUS == "1") && (B.iStatus == 1)

the statement does not execute.
To execute you need to use this and perform some actions on it. For example, Lqry.Count() perhaps.

Third,
Syntax: A valid statement would look like

List<int> someCollection = new List<int>() { 3,6,9,12,1,17,4 };
var result = from x in someCollection
             select x;

result would be IEnumerable<int>
So, in the above query, the please change the syntax.
Perhaps,

var Lqry = from A in DC.CLRN_Tables
           join B in DC.CLRN_Tables2 on R.ID equals B.ID
           where (A.STATUS == "1")&&(B.iStatus == 1)
           select A;

Fourth,
Do not mix LINQ and SqlCommand. It is always better to have either of them.

Fix these minor things and your code should work.

var Lqry = from A in DC.CLRN_Tables
           join B in DC.CLRN_Tables2 on A.ID equals B.ID
           where (A.STATUS == "1")&&(B.iStatus == 1)
           select A;