Court Summon to official address

My real uncle has sold off ancestral property in 2011 in Gorakhpur District of UP secretly without informing my mom n mausi. He has falsely declared himself as the only heir and sold the property. Now, my mom has filed a civil case against him and also planning to file a fraud case for illegally declaring himself as the sole heir of the property. Problem is that we don't know his residential address and only his official address. . He works in govt. Job .. In railways. Can Court summon be sent to official address if residential address is not known ? What to do in such situation ?