The answer is presidential
In a parliamentary system, the executive branch derives its legitimacy from and is directly accountable to the legislature (parliament); the head of state is usually different from the head of government. This does not accurately describe the Russian political system under Putin.
In a presidential system, the president is the head of state and government, and the executive branch is separate from the legislative branch. Russia, under Putin, operates under a system where the president holds significant power, making this the most accurate description.
A semipresidential system features both a president and a prime minister, where the president has significant powers but shares executive responsibilities with the prime minister. While Russia has elements of this system, the power is heavily concentrated in the presidency, making "presidential" a more fitting description.
While some may argue that Putin's rule has authoritarian characteristics, the official structure of the Russian government is not defined as dictatorial. The term "dictatorial" refers more to the style of governance rather than the formal structure.