Part 1: From your error it seems that you are not able to access even table t1 because your error says
Invalid object name 't1'
An easy fix to get access to the table is, just connect to your database, open a NewQuery window and re-execute the query. I'm sure you will be able to access the table.
Part 2: Now if you see your query, then query itself is wrong. You need to use
IN operator instead of
= operator, because you want to filter out rows based on multiple values. So simply re-write your query as follows.
select * from t1 where c IN ('US', 'UAE')