Canberra Girls Grammar School student Maryam Eghtedari.

Canberra Girls Grammar School student Maryam Eghtedari. Photo: Supplied

Two international students who spoke English as a second language and arrived in Australia at the start of Year 11 have achieved Canberra's equal top Australian Tertiary Admission Rank of 99.95.

Narrabundah College student Rongkai Tian arrived in Australia from China 2½ years ago.

He lived alone and put himself through an intensive six-month English bridging course at Narrabundah College before starting Year 11 in 2011.

Narrabundah College student  Rongkai Tian.

Narrabundah College student Rongkai Tian. Photo: Supplied

Canberra Girls Grammar School student Maryam Eghtedari arrived at the start of 2011 from Iran with her family. Her older sister also studied at Girls Grammar and completed Year 12 last year with an ATAR of 99.8.

While the ACT college system's top achievers take part in a ceremony at the Playhouse on Tuesday, Mr Rongkai and Ms Eghtedari were celebrating the end of Year 12 in their home countries.

But both will be returning to Australia to take up places at university. Mr Rongkai is keen to enrol in engineering at either Sydney or Melbourne University and Ms Eghtedari is hoping to study medicine at NSW or Sydney University.

Narrabundah College principal Kerrie Grundy described Mr Rongkai's progression through college as a story of courage and commitment.

He lived on his own in Gungahlin, and took responsibility for his own food, clothing and transport.

Mrs Grundy, who told him on Monday morning of his results, said he was thrilled and humbled by his score.

"I am sure it has not been easy for him to put himself through college but he has been an inspiration to the rest of the college community," she said.

Mr Rongkai completed a double major in specialist maths and majors in physics and chemistry. He continued to study English, completing a major.

Mrs Grundy described him as "an exceptional student - hard-working, methodical and meticulous, modest, intuitive and gifted''.

Mr Rongkai also made a significant contribution to the college community, producing a maths tutorial book to help other students, founding a peer mentor program and mentoring his peers in years 11 and 12 in maths.

Ms Eghtedari completed a double major in specialist maths, majors in chemistry and physics and a major in English second language.

Her principal, Anne Coutts, said: "What is extraordinary is that Maryam has recorded this result with English as her second language. She arrived from Iran at the start of Year 11 last year and, we'd have to say, has settled in extremely well."

Mrs Coutts said Ms Eghtedari was a "dedicated and hardworking student with an innate analytical ability to master even the finest detail."

She noted the all-girls school was also showing its strength and consistency in a number of traditionally male subjects.

"We have significantly strengthened the maths and science faculties at the school and our students are forging ahead in these male-dominated fields. For Canberra Girls Grammar to top the ACT two years in a row is a credit not only to our students, but our excellent teaching staff."