Yes you can. The clause in the Achievement Award just means that you can have either (TA/RA/GA) or Achievement Award at a given time. In case you are offered a TA/RA/GA, then your Achievement Award will get revoked and your TA/RA/GA would come into effect. Also, depending on the number of hours you need to work in your TA/RA/GA you could possibly work some OPS job as well – just keep in mind that the total number of hours should not exceed 20 per week. Note: OPS and Achievement Award have no connection what-so-ever.