Yes — "if" is capitalized in title case because it is a subordinating conjunction.
"If" is a subordinating conjunction and is capitalized in title case. AP Style, Chicago Style, MLA Style, NYT Style, and AMA Style all capitalize subordinating conjunctions, distinguishing them from the coordinating conjunctions that are lowercased.
Subordinating conjunctions include "if," "when," "because," "although," "while," "unless," and "since." All of these are capitalized in title case because they introduce dependent clauses and carry more semantic weight than coordinating conjunctions.
The distinction matters in practice. "What If We Tried" capitalizes "If" in AP Style, Chicago Style, and MLA Style. A writer who lowercases "if" is incorrectly extending the coordinating conjunction rule to subordinating conjunctions.
APA Style, Wikipedia Style, and Sentence Case lowercase "if" in the middle of a title as part of their blanket sentence case rule.
The title case rule about lowercasing conjunctions applies only to coordinating conjunctions — the FANBOYS group: for, and, nor, but, or, yet, so. "If" is a subordinating conjunction and is not in that group. It is capitalized in all title case styles.