Dear Aspirant, I really appreciate your career option, that you want to become professor in geology. Let me explain, the become professor you have to study geology in graduation as one subject, in masters as major subject and finally you have to do doctoral degree in geology also.
Even you can get entry into a college after your masters degree, but you will have to clear NET in Geology. Even after PhD degree, to get entry as lecturer or assistant professor in University, again NET (national eligibility test) or state level entrance test (SLET) certificate is must.
There are various colleges and universities i India, where you can pursue your career.
Here is the list of some colleges:
Vikram University, Ujjain
Chaudhary Charan Singh University Meerut, Uttar Pradesh
Chatrapati Shahuji Maharaj University, Kanpur, UP
Devi Ahilya Vishvavidhalaya, Indore, Madhaya Pradesh
Dr. Hari SIngh Gaur Vishwavidhala, Sagar Madhaya Pradesh
Guru Ghasi Das University, Bilaspur, Chattis Garh
Pt. Ravi Shankar Shukla University, Rai Pur, Chattis Garh
University of Lucknow, Lucknow, UP
Mahrashi Dayanand University, Rohtak, Haryana
Kumaun University, Nainital, Utrtakhand
Guru Nanak Dev University, Amirtsar, Punjab

Kanpur University, Kanpur UP
University of Delhi, Delhi
HNB Garhwal University, Srinagar, Uttrakhand
Gujrat University, Ahemdabad
Aligarh Muslim University, Aligarh, UP
Banaras Hindu University, Banaras, UP
and many more are there,
It all depends upon your interest and selection. Every University has some entrance test or merit based entrance.
In India, to become professor, you have to join a University and work for 10-15 years. Your entry level will be Assistant Professor, after six to eight years (on the basis of time bound promotion), you will be promoted as Associate Professor and again after eight years, you will be promoted to Professor (Full).
To become an Associate Professor and then Professor, you have to attain lot of things, in the form of reserch publications, book chapters, review articles in reputed journals, research projects from funding agencies, and guided doctoral degree students.
Your academic career should be clean and bright.
To become Professor in Geology in western Universities, NET is not required, but you have to do Post Doctoral Degree Fellowship(PDF) for once or twice. Then your enry level will be at Assistant Professor, after that it all depends upon your performance.
If you have material in you, you can achieve, what you wish....

Hello,

To become a Professor in Geology subject, you have to purse graduation and then postgraduation in Geology.

After completing the postgraduation, you will have to qualify the UGC NET Exam which is mandatory to become a lecturer. There are also such exams like UGC NET which are SET, SLET, ICAR, etc. But appearing in the UGC NET will be the best option for you.

The exam is conducted twice a year by National Testing Agency for 81 subjects including the Geology.

Once you qualify this exam, the officials will provide you a certificate that can be used to appear in interviews which are conducted by various colleges and institutes to recruit the candidates for the pot of Assistant Professor.

I hope it helps!