In whose ashram did the Beatles compose rock music in 1968 influenced by classical music?

The correct option is Maharshi Mahesh Yogi Ashram.

In February 1968, the English rock band The Beatles traveled to Rishikesh in northern India to attend a session of Transcendental Meditation at the ashram of Maharshi Mahesh Yogi.

During their stay at the ashram, the band members engaged in deep meditation and experienced a very creative period. They composed dozens of songs there, many of which were influenced by Indian classical music and spiritual themes, and later featured on their famous 1968 double album, The Beatles (commonly known as the White Album).