Hi Madhu,
For SaaS connectors, we do not have the regular connector rules, but SailPoint do provides another way called as customizers (which use typescript). These work like webservice before and after operation rules, where the request can be intercepted, customized before the actual call. You can find more details in the below links:
Connectivity Customizers | SailPoint Developer Community.
Regards,
Uday Kilambi