Gillane first came to prominence in [Ardscoil Rís, Limerick|Ardscoil Rís in Limerick. On 22 February2014, he was introduced as asubstitute when Arscoil Rís defeated Scoil na Trionóide from Doon by 2-13 to 0-04 in the final of the Harty Cup.
Gillane joined the Patrickswell club at a young age and played in all grades at juvenile and underage levels. On 23 October 2016, Gillane won a Limerick Hurling Championship medal after scoring seven points from wing-forward in Patrickswell's 1-26 to 1-07 defeat of Ballybrown in the final. Gillane lined out in a second Limerick Championship final on 6 October 2019. Playing at right corner-forward he scored six points and collected a second winners' medal following the 1-17 to 0-15 defeat of Na Piarsaigh.
Limerick
Minor and under-21
Gillane first played for Limerick as a member of the minor team. On 22 July 2014, he was an unused substitute when Limerick won the Munster Championship after a 0-24 to 0-18 defeat of Waterford in a replay of the final. On 28 June 2016, Gillane made his first appearance for the Limerick under-21 team in a 3-19 to 2-15 defeat of Cork. In his second season on the team he won a Munster Championship medal after a 0-16 to 1-11 defeat of Cork in the final. On 9 September2017, Gillane was at right wing-forward in Limerick's 0-17 to 0-11 defeat of Kilkenny in the All-Ireland final. He was later named on the Bord Gáis EnergyTeam of the Year.
Senior
On 4 June 2017, Gillane made his first appearance for the Limerick senior team in a 3-17 to 2-16 defeat by Clare in the Munster Championship. On 19 August 2018, Gillane scored three points, including one from a free, from right corner-forward when Limerick won their first All-Ireland title in 45 years after a 3-16 to 2-18 defeat of Galway in the final. He ended the season by being nominated for an All-Star Award. On 31 March 2019, Gillane was selected at right corner-forward for Limerick's National League final meeting with Waterford at Croke Park. He collected a winners' medal after top scoring with 1-09 in the 1-24 to 0-19 victory. On 30 June 2019, Gillane won a Munster Championship medal after scoring four points from right corner-forward in Limerick's 2-26 to 2-14 defeat of Tipperary in the final. He ended the year by receiving his second All-Star nomination.