Generating random numbers in oracle without dbms_rand

If you're really desperate you could roll your own, eg here's an LG one

SQL> create or replace
  2  package global is
  3    a number := to_number(to_char(systimestamp,'FF'));
  4  end;
  5  /

Package created.

SQL>
SQL> create or replace
  2  function rand(r in number) return number is
  3
  4    mill  constant  number:=100000000;
  5    ten_thou constant number:=10000;
  6    lg_num  constant  number:=31415821;
  7
  8    v number;
  9    w number;
 10    x number;
 11    y number;
 12    z number;
 13
 14  begin
 15    w:=trunc(global.a/ten_thou);
 16    x:=mod(global.a,ten_thou);
 17    y:=trunc(lg_num/ten_thou);
 18    z:=mod(lg_num,ten_thou);
 19    v := mod((mod(x*y+w*z,ten_thou)*ten_thou+x*z),mill);
 20    global.a:=mod(v+1,mill);
 21    return(trunc((trunc(global.a/ten_thou)*r)/ten_thou));
 22  end;
 23  /

Function created.

SQL>
SQL> select rand(100) from dual;

 RAND(100)
----------
        21

SQL> select rand(100) from dual;

 RAND(100)
----------
        72

SQL> select rand(100) from dual;

 RAND(100)
----------
         1

SQL> select rand(100) from dual;

 RAND(100)
----------
        43

but random number generation is a science so you should be aware of the all of the limitations and drawbacks of rolling your own.

https://en.wikipedia.org/wiki/Linear_congruential_generator

So your best bet is to get appropriate access to the appropriate packages.