Hi @krishna_garikapati,
This issue is related to cascading metadata feature:
Long story short, you can control visibility or other aspects of field in metadata schema base on value(s) of other field. This can be done using Rule editor.
In your particular example it looks that one or many fields in your schema has a Rule that rely on different field, and you are trying to remove the field that is dependency to others.
So you first have to delete this relationship, before you will be able to successfully remove filed that is used by other fields.
Information about dependency is stored under granite:data node located under main node that defines specific filed in you schema.

To identify this you can either verify all the fields in your schema, checking Rule section. Or you can run below query.
The query search for all the fields that has any dependency, you can modify query on your own changing condition related to cascadeVisibilityFrom property.
SELECT * FROM [nt:base] AS s WHERE ISDESCENDANTNODE([/conf]) AND s.[sling:resourceType] = "dam/gui/components/admin/schemafield" AND s.[/granite:data/cascadeVisibilityFrom] <> ""
More specific query, that will look only for fields that depends on Language property (./jcr:content/metadata/dc:language)
SELECT * FROM [nt:base] AS s WHERE ISDESCENDANTNODE([/conf]) AND s.[sling:resourceType] = "dam/gui/components/admin/schemafield" AND s.[/granite:data/cascadeVisibilityFrom] = "./jcr:content/metadata/dc:language"