Bikramjit comes on the back of a title-winning campaign with the Chennaiyin FC, while Rana played a pivotal part in helping Mohun Bagan finish third in the I-League apart from a semi-final finish in the inaugural Super Cup.
Bikramjit started his career with the Pailan Arrows back in 2010 before moving to Churchill Brothers, where he guided the Goan club to an I-League title in 2012 and then a Federation Cup in 2013-14 season.
The 25-year old then moved to Kolkata giants Mohun Bagan where he continued his successful career as he bagged both the I-League and the Federation Cup in successive seasons during his three-year stint with the club.
Prior to Chennaiyin FC in the ISL, Bikramjit starred for FC Goa in the first two editions of the tournament, before being roped in by ATK where he was part of the title-winning squad.
"This is a club which is very close to my heart as I feel at home here. Dynamos have a strong group of players in the squad and I am really excited and looking forward to contributing as much as I can. I have had two really successful ISL seasons and I want to make it three in a row by helping Delhi win their first title, Bikramjit said.
Joining Bikramjit in the squad will be Kolkata-born defender Rana.
The 27-year old starred in West Bengal's Santosh Trophy triumph in 2016-17 and also won the Sikkim Gold Cup last year with Mohun Bagan.
Rana's addition will provide a major boost in the backline of the squad.
"I am looking forward to my first ISL season. I've had a strong season with Mohun Bagan in the I-League as well as the Super Cup, but I want to go one better and win the titles this time around, Rana said.
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