Complex sentence: Santosh, along with another party activist Kuldeep, was going to AAP's office, riding a small motorcycle, in Kaushambi in Ghaziabad, Uttar Pradesh, when a car rammed into the bike from behind and sped away.
Split into simpler sentences: Santosh, along with another party activist Kuldeep, was going to AAP's office, riding a small motorcycle, in Kaushambi in Ghaziabad, Uttar Pradesh, when the incident occurred. A car rammed into the bike from behind and sped away.