Complex sentence: In 1990, he became a member of the upper house of the Parliament of India, which is known as the Rajya Sabha, and in 1998 he was elected to the lower house, called the Lok Sabha.
Split into simpler sentences: In 1990, he became a member of Rajya Sabha, the upper house in the Parliament of India. In in 1998 he was elected to the lower house Lok Sabha.