What Do I need to legalised my two kids to become Nicaraguan citizen's, they are Americans and would like double citizenship for them as I'm a Nicaragua native.?

Speak English then Indian

First of all you need to learn how to write but I guess you are way pass that stage. you cannot legalize (not legalised) anyone to become a Nicaraguan citizen. THEY NEED TO CLAIM CITIZENSHIP BY OBTAINING A NICARAGUAN PASSPORT................... PLAIN AND SIMPLE

Dual nationality is acquired by their children when the Nicaraguan father or mother registers their minor child in the Nicaraguan consulate or embassy. The requirements, I do not know them but they must be several and have the supporting documentation of the Nicaraguan.