Question:
Which political party did R.N. Upadhyaya belong to in Jul, 1965?

Context:
 R.N. Upadhyaya is a member of the Communist Party of India from Jan, 1952 to Jan, 1964. 
 R.N. Upadhyaya is a member of the Revolutionary Socialist Party from Jan, 1940 to Jan, 1952. 
 R.N. Upadhyaya is a member of the Communist Party of India (Marxist–Leninist) Liberation from Jan, 1997 to Jan, 1997. 
 R.N. Upadhyaya is a member of the Communist Party of India (Marxist-Leninist) from Jan, 1969 to Jan, 1972. 
 R.N. Upadhyaya is a member of the Communist Party of India (Marxist) from Jan, 1964 to Jan, 1967.

Answer:
Communist Party of India (Marxist)