The question is about the recommendation on the 10+2+3 education structure in India, which refers to the school and higher education system. This educational structure was part of the Statement on the National Policy on Education, 1968.

Let's analyze each of the commissions mentioned in the options:

1. Kothari Commission: Officially known as the "Education Commission" (1964–66), it was led by Dr. D.S. Kothari. This commission recommended the 10+2+3 educational structure, which was later incorporated into the National Policy on Education of 1968. The Kothari Commission aimed to align education with the socio-economic needs of the country and emphasized integrated educational structures catering to different levels of learning.
2. Mandal Commission: Known for its focus on identifying the socially and educationally backward classes and recommending measures for their upliftment. It did not directly deal with the restructuring of the education system.
3. Ramamurti Commission: Formed in the late 1980s, aimed at reviewing the National Policy on Education 1986. It came after the adoption of the 10+2+3 system.
4. Mudaliar Commission: Also known as the Secondary Education Commission (1952-53), it focused on reforms at the secondary education level but preceded the 10+2+3 system.

Among these options, the Kothari Commission is credited with the recommendation of the 10+2+3 structure.

Therefore, the correct answer is Kothari Commission.