The primary mode of teacher recruitment in Maharashtra government schools is through:

Teacher Eligibility Test (TET)
Direct recruitment by schools
Campus placements
State Public Service Commission

The primary mode of teacher recruitment in Maharashtra government schools is through the Teacher Eligibility Test (TET). The TET is a state-level exam that is conducted by the Maharashtra State Board of Secondary and Higher Secondary Education (MSBSHSE). The exam is mandatory for all candidates who wish to teach in government schools in Maharashtra. The TET consists of two papers: Paper I and Paper II. Paper I is a paper on general knowledge and Paper II is a paper on pedagogy. The TET is a qualifying exam, which means that candidates who clear the exam are eligible to apply for teaching positions in government schools. The final selection of candidates is based on a merit list prepared on the basis of the TET scores and the interview scores.

The other options are not the primary mode of teacher recruitment in Maharashtra government schools. Direct recruitment by schools is a mode of recruitment that is used by some schools to recruit teachers. However, this mode of recruitment is not very common. Campus placements are a mode of recruitment that is used by some colleges to recruit teachers. However, this mode of recruitment is also not very common. The State Public Service Commission (SPSC) is a government body that conducts exams for various government jobs. However, the SPSC does not conduct an exam for the recruitment of teachers in government schools.

In conclusion, the primary mode of teacher recruitment in Maharashtra government schools is through the Teacher Eligibility Test (TET).