If you want to reset the entire object, just reset the variable back to {};

cfamFwdDtls = {}; 
// or
cfamFwdDtls = new Object; 
// will prevent garbage collection
delete cfamFwdDtls;

However, if you want a more fine-grained way of "resetting" the object, you are going to need to define what specifically your requirements for a reset are. Regardless, you can always iterate through the object and make the necessary objects.

for (var key in cfamFwdDtls) {
    if (typeof cfamFwdDtls[key] == "string") {
        cfamFwdDtls[key] = '';
    } else if (Array.isArray(cfamFwdDtls[key])) {
        cfamFwdDtls[key] = [];
    } else {
        delete cfamFwdDtls[key];
    }
}

The above definition could be a possible way to define your particular situation since I only see strings and arrays in your object. If the key is neither of those, it would just delete the key. This could be tailored as you find necessary.

for (var entry in cfamFwdDtls) delete cfamFwdDtls[entry];

If you simply reassign to {}, you'll get in trouble if there are multiple references to your object. Also may face garbage collection issues.

there is alternative for this if you want to remove object.Something like this

delete cfamFwdDtls;

you can use delete keyword for deleting a object.

more details read

example

function getJson(){
   return {
            cndtwizid: [],
            clientIdsInstnIds: [],
            positioncd: '',
            positionCnt: '',
            rcrtrInstnId: '',
            positionLocation: {
                cntryIdFrCndt: '',
                stateIdFrCndt: '',
                zipIdFrCndt: '',
                cityIdFrCndt: ''
            },
            searchPstnSkill: []
         };
}

var data = getJson();
data.positioncd = 'xyz';
data.rcrtrInstnId = 'abc';

$.ajax(...){
}
success(response){
   data = getJson(); //re-initialize structure
}

The Problems

When I ran into this I wanted to solve two issues.

1. Have one location for a complex structure definition.
2. Reassurance the entire definition is reset.

Solutions

The basic idea is have a function return the empty structure. If it is not in a function you could change the structure itself not the instance of the structure.

Examples

Class

I personally use this but I also include the API functions in the class and make it an HTTP service.

class complexStructure {
  constructor () {
    this.payload = resetPayload();
  }
  resetPayload () {
    this.payload = {
      cndtwizid: [],
      clientIdsInstnIds: [],
      //...
    };
  }
}

Function

function resetStructure () {
  return {
    cndtwizid: [],
    clientIdsInstnIds: [],
    //...
  };
}

let resetStructure = resetStructure()