As I read in general visitor visa Terms & Condition, I would only be granted to stay up to 6 months in UK. However I am planning to apply for General Student Visa to further my studies. Would it be possible for me to enter UK as visitor for first 6 months/less before I apply for student visa in the same year if I want to travel and study on the same year?
This is fine, you can visit the UK and subsequently apply for a student visa.
What you CANNOT do is try to apply from within the UK. Mark and Burhan (to whom thanks) have correctly observed that the UK does not allow for in-country switches if a person's immigration status is visitor. That rule applies across the board for all types of visas.
Part of your landing interview is to convince the Immigration Officer that you will leave at the conclusion of your visit, and if you conceal that you really want to stay on they will get very upset when you try to apply and matters will be worse. That type of performance may result in your being unable to apply successfully from outside the UK later.
But it's certainly OK, to have a visit, then leave and apply. If you are applying as a short-term student (6 months or less), you can apply at any British mission abroad that functions as an issuing post. If you want a longer-term visa, you need to apply from Malaysia. The controlling reference is Paragraph 28 of the Immigration Rules.
An applicant for an entry clearance must be outside the United Kingdom and Islands at the time of the application. An applicant for an entry clearance who is seeking entry as a short-term student must apply to a post designated by the Secretary of State to accept applications for entry clearance for that purpose and from that category of applicant. Subject to paragraph 28A, any other application must be made to the post in the country or territory where the applicant is living which has been designated by the Secretary of State to accept applications for entry clearance for that purpose and from that category of applicant. Where there is no such post the applicant must apply to the appropriate designated post outside the country or territory where he is living.
...combined with Paragraph 245ZU of the rules...
All migrants arriving in the UK and wishing to enter as a Tier 4 (General) Student must have a valid entry clearance for entry under this route. If they do not have a valid entry clearance, entry will be refused.