How to set company wise month

SQL> select MAX(ADD_MONTHS(trunc(at_dt,'MON')+25,-1)) into :dt1 from emp_attn_data
  2    where at_dt <> (select max(add_months(trunc(at_dt,'mon')+25,0)) from emp_attn_data);

MAX(ADD_M
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26-JUL-17

SQL> select MAX(ADD_MONTHS(trunc(at_dt,'MON')+25,-1)) into :adt from emp_attn_data;

MAX(ADD_M
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26-JUL-17

SQL> select MAX(trunc(at_dt,'MON')+24) into :adt from emp_attn_data;

MAX(TRUNC
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25-AUG-17