Let \({\mathbb {F}}_q\) be the finite field of order \(q=p^m\) where p is a prime, and m is a positive integer. This work introduces \({\mathbb {F}}_q{\mathcal {R}}\) -linear \((\varTheta ,\varDelta _\varTheta )\) -cyclic codes where \({\mathcal {R}}={\mathbb {F}}_q+u{\mathbb {F}}_q\) with \(u^2=u\) , i.e., \((\varTheta ,\varDelta _\varTheta )\) -cyclic codes over \({\mathbb {F}}_q{\mathcal {R}}\) . With the help of the decomposition method, we study the structural properties and determine the generator polynomials of \({\mathbb {F}}_q{\mathcal {R}}\) -linear \((\varTheta ,\varDelta _\varTheta )\) -cyclic codes. Further, we define the Gray map over \({\mathbb {F}}_q{\mathcal {R}}\) and find the Gray images of \({\mathbb {F}}_q{\mathcal {R}}\) -linear \((\varTheta ,\varDelta _\varTheta )\) -cyclic codes over \({\mathbb {F}}_q\) . Finally, with the help of our established results, we have constructed some new codes corresponding to \({\mathbb {F}}_q{\mathcal {R}}\) -linear \((\varTheta ,\varDelta _\varTheta )\) -cyclic codes.