Answer : 3. "छठे विधानसभा चुनाव में "
Explanation :

1. The first assembly elections in Rajasthan were held in the year 1952. The tenure of the assembly formed during this period lasted till 1952.

2. The number of members in the first assembly was 160. When Ajmer merged with Rajasthan state in the year 1956, the number of members was increased to 190.

3. The number of members in the second assembly (1957-62) was. Whereas in the fourth assembly (1967-72) there were 184 members.

4. From the sixth (1977-80) Legislative Assembly, the number of members increased to 200.