Hi i just want to get something that connect my osmo mobile to regular tripod like manfrotto, what accessory i may need?thanks!

You have a couple different options.  You could use the "OSMO Base" that costs $10, it has a Threaded hole on the bottom that connects to standard 1/4 20 thread http://store.dji.com/product/osmo-base or you could use the DJI extension Rod http://store.dji.com/product/osmo-extension-stick or you could just improvise something.  I'd go with the OSMO Base for $10 first and see if that meets your needs

All you need is some form of adapter / right angled pivot system that will allow you to connect a standard tripod.

Heres' what I did with a 15mm rod (2.5") + 1/4" to 1/4" double end screw + 15mm rod clamp mount. You can side mount the handle to adjust the angle enough to see straight down or add a second clamp mount and longer rod and mount the osmo inverted.     

I should note that my setup was going a regular stand rather than a tripod so depending on the size of your tripod head you might need a longer 15mm rod to get enough clearance.  

A 7" or 11" articulating arm is a sound accessory to have AMAZON lists a large selection.