A noun phrase can be modified by a following participial clause, i.e. a clause introduced by a participle.
Examples:
A cat [climbing a tree] ...
A cat [attacked by a dog] ...
A man [smoking] ...
A building [being demolished with a wrecker ball] ...
As you see, both present participles (-ing) and past participles (-ed and various other formations) can be used in this construction. The modifying clause does not contain a finite verb (such as is). None of my examples is a sentence, as they all lack a main verb: they are more complex noun phrases, which could serve as subject or object (or other roles).
So the structure of your example is
[[An Integrated Textile Park (ITP)] [being developed at Edlapadu on Guntur-Chennai National Highway]] is expected to give the much-needed fillip to textile industry in Andhra Pradesh.
where the whole of the outer set of [ ] marks the subject. The verb in the participle is passive, so being developed as opposed to developing (which would be active).