It is working but I want only unit should be passed
Can I give unit element as madatory under any elements
So I am led to understand that you only want to write xs:any under technicaldata but all the same you want whatever being admitted as pertinent to xs:any contains a unit element ("... under any elements" with "under" meant descendant of technicaldata, and "any" refers to xs:any.)
 First, you must understand in order to validate a "unit" element, the engine must perform validaion in order to validate it. Therefore, processContents="skip" cannot be.
So what to do? You must strengthen it to processContents="lax", strengthen to "strict" seems not what you want at all.
The validation according to lax entails that you must have the element unit "defined" as global element in the schema... So you first must isolate it and define it as global (in case you don't understand the concept, it means xs:element for "unit" must be the direct child of xs:schema element.
If your ChartLimit8 be complex type, change the above accordingly.
 Then you must understand that any other element such as co2NefzGas etc I suppose are defined only locally (other than globally) in the original schema. And then you want to spare any of them. That is fine. If by bad luck you have some globally defined xs:element with name that you want to pass to technicaldata as its descendant, then you have to make sure you have all those having unit as descendant having the cardinality minOccurs="1" that means mandatory exactly in narrative/normative term. (I am not sure you really understand but leave it as such for the moment.) Furthermore, those explicit globally defined element containing unit element must be written with a reference to the global element unit so defined. For instance this.
The only rigid thing I want to illustrate is the way to write the "unit" element (minOccurs="1" by default which means mandatory, if you want multiple unit, you add maxOccurs="unbounded" tp it, otherwise the default is maxOccurs="1".) All the rest y, z their types and cardinality are for illustration only. With that, the x will also be validated together with unit (mandatory) too.
I hope you understand... otherwise, I just have to say it is not that elementary as an excuse not able to convey to you the proper way of doing it in that approach.