To determine the formal requirements for a post-graduate degree holder with 55% marks intending to pursue research for the award of a Ph.D. degree, we need to analyze each option provided in the context of typical Ph.D. program requirements:

1. Appearing in an admission test of a university: Most Ph.D. programs require candidates to take an entrance or admission exam, which assesses the candidate's research aptitude, subject knowledge, and analytical skills. This step helps universities select suitable candidates for their research programs.
2. Submitting an application for enrollment: A formal application is necessary to enroll in a Ph.D. program. This allows the university to officially recognize and process the candidate's intent to join the research community.
3. Submitting a proposal for the research: A detailed research proposal is crucial as it outlines the research objectives, methodology, and significance. It is often required during the application process to understand the candidate's research direction.
4. Getting the proposal approved by the relevant body of the university: Once submitted, the research proposal typically needs approval from a university committee or board. This ensures that the research is viable and aligns with academic standards.
5. Attending mandatory course work: Most Ph.D. programs include mandatory coursework to provide the foundational knowledge and skills necessary for conducting research. It also helps in the comprehensive understanding of the chosen field.

Now, let's consider the incorrect options:

• Attending a coaching institute: This is not a formal requirement for Ph.D. enrollment. Coaching institutes may help prepare for entrance exams but are not part of the formal process.
• Consulting an expert teacher: While valuable for guidance, consulting a teacher is not a formal registration requirement for Ph.D. programs.
• Discussing the research proposal with a peer group: Although beneficial for feedback, it is not a formal requirement in the enrollment process.
• Getting the opinion of the expert on the research theme: Helpful but not formally required for enrollment or proposal acceptance.

Therefore, the correct combination of formal requirements for enrolling in a Ph.D. program includes options (a), (d), (e), (h), and (i), which align with the necessary academic and administrative steps required by universities.