SQL> desc del;
 Name                                      Null?    Type
 ----------------------------------------- -------- -------------
 VAR1                                               NUMBER
 VAR2                                               NUMBER

SQL> ed
Wrote file afiedt.buf

  1* alter table del rename column var1 to i
SQL> /

Table altered

alter table del
   rename column var1 to i
   rename column var2 to j
/

SQL> alter table t rename column c1 to v1 rename column c2 to v2;
alter table t rename column c1 to v1 rename column c2 to v2
*
ERROR at line 1:
ORA-23290: This operation may not be combined with any other operation