Complex sentence: They were impressed with Brando's performance and approved his casting in the title role, under the condition that Brando accept less than his usual fee and put up a bond insuring against delays in production.
Split into simpler sentences: They were impressed with Brando's performance and approved his casting in the title role, but with conditions. Brando had to accept a reduction from his usual fee, and put up a bond insuring that he would not cause any delays in production.