Complex sentence: Panchayati Raj has a three-tier structure in the state: the atomic ones are Gram Panchayats, the block-level organizations are called "Panchayat Samiti", and district-level organizations are named "Zilla Parishad".
Split into simpler sentences: Panchayati Raj has a three-tier structure in the state. The block-level organizations are called "Panchayat Samiti", and the district-level organizations are named "Zilla Parishad".