Are there smaller packages for Standard rcl (resistor, inductance, capacitor) than 0402mm
Your best bet is going to stick to 01005 available from common distributors like Digikey.
Note the caveats with the size:

01005 resistors can only handle ~1/32 W power. Sizes below 01005 are not commercially common -- digikey sells only one resistor with a smaller size, with a resistance of 0.02 ohms, and a minimum order quantity of 40000.
01005 capacitors can easily range well past 100 pF but may have lower voltage tolerance, tempco, etc. Below that, you have a tiny selection of specialty caps.
01005 inductors are available; the largest I saw was 56 nH. Current handling is relatively limited. Below 01005/0402 metric, none are commercially listed.

Past 01005 there are very few options available. There are rare 008004 packages, as well as custom ones, but if you really need the miniaturization, you may need to consider integration on an IC (of course, scaling your design and passives to values achievable on a process that you can afford).